Introduce new CLI/configuration code for mailutils applications.

The new API is to replace libmu_cfg and libmu_argp.  A smooth transition
is scheduled, during which the two APIs will coexist,

* configure.ac: Build libmailutils/cli/Makefile
* include/mailutils/cli.h: New file.
* include/mailutils/Makefile.am: Add cli.h
* libmailutils/cli/Makefile.am: New file.
* libmailutils/cli/capa.c: New file.
* libmailutils/cli/cli.c: New file.
* libmailutils/cli/stdcapa.c: New file.
* libmailutils/Makefile.am (SUBDIRS): Add cli.

* include/mailutils/cfg.h (mu_cfg_parse_hints): New members: append_tree
and data.
(MU_PARSE_CONFIG_LINT): New flag.
* include/mailutils/diag.h (mu_program_name)
(mu_full_program_name): Remove const qualifier.
* include/mailutils/locker.h (mu_locker_set_default_external_program):
Argument is const.
* libmailutils/base/locker.c: Likewise.

* include/mailutils/opt.h (mu_progname, mu_absprogname): Replace
with mu_program_name and mu_full_program_name.
(mu_set_progname): Rename to mu_set_program_name.
(mu_parseopt) <po_data>: Change type to void *.
(po_help_hook, po_version_hook): Change signatures.
(mu_parseopt_error): New function.
* libmailutils/opt/progname.c (mu_progname, mu_absprogname): Replace
with mu_program_name and mu_full_program_name.
(mu_set_progname): Rename to mu_set_program_name.
* libmailutils/opt/help.c: Minor changes
* libmailutils/opt/opt.c (parse_error): Rename to mu_parse_error (extern).
(next_opt): Fix permutations.
* libmailutils/tests/parseopt.c: Reflect changes.
* libmailutils/tests/parseopt17.at: Improve test case
* libmailutils/tests/parseopt_help05.at: Reflect changes.
* libmailutils/tests/parseopt_help07.at: Reflect changes.

* include/mailutils/stdstream.h (mu_program_name): Remove qualifier.

* libmailutils/cfg/driver.c (mu_cfg_tree_reduce): Remove useless condition

* libmailutils/cfg/lexer.l (mu_cfg_parse_file): Additional info messages.
* libmailutils/cfg/parser.y (mu_cfg_parse_config): Join in
the append_tree.
* libmailutils/diag/diag.c (mu_program_name, mu_full_program_name)
(mu_set_program_name): Remove. Declared elsewhere.
* libmu_sieve/conf.c: Add new configuration code. Mark old text for
removal.
* libmailutils/tests/tcli.c: New program.
* libmailutils/tests/Makefile.am: Add tcli.c

20 files changed, 1149 insertions, 64 deletions

diff --git a/libmailutils/Makefile.am b/libmailutils/Makefile.am
index 7a5270c4c..82550c23f 100644
--- a/libmailutils/Makefile.am
+++ b/libmailutils/Makefile.am
@@ -17,7 +17,7 @@
 # <http://www.gnu.org/licenses/>.
 
 SUBDIRS = \
- auth base address list sockaddr cidr cfg diag\
+ auth base address list sockaddr cidr cfg cli diag\
  filter mailbox mailer mime msgset opt server string stream stdstream\
  property url imapio datetime . tests 
 
@@ -33,6 +33,7 @@ libmailutils_la_LIBADD = \
  sockaddr/libsockaddr.la\
  cidr/libcidr.la\
  cfg/libcfg.la\
+ cli/libcli.la\
  datetime/libdatetime.la\
  diag/libdiag.la\
  filter/libfilter.la\
diff --git a/libmailutils/base/locker.c b/libmailutils/base/locker.c
index b4663b948..c4fe993bf 100644
--- a/libmailutils/base/locker.c
+++ b/libmailutils/base/locker.c
@@ -242,7 +242,7 @@ mu_locker_set_default_expire_timeout (time_t t)
 }
 
 int
-mu_locker_set_default_external_program (char *path)
+mu_locker_set_default_external_program (char const *path)
 {
   char *p = strdup (path);
   if (!p)
diff --git a/libmailutils/cfg/driver.c b/libmailutils/cfg/driver.c
index c0cd2d5d9..f2a43a367 100644
--- a/libmailutils/cfg/driver.c
+++ b/libmailutils/cfg/driver.c
@@ -463,7 +463,7 @@ mu_cfg_tree_reduce (mu_cfg_tree_t *parse_tree,
                     void *target_ptr)
 {
   int rc = 0;
-
+  struct mu_cfg_cont *cont;
   if (!parse_tree)
     return 0;
   if (hints && (hints->flags & MU_PARSE_CONFIG_DUMP))
@@ -477,13 +477,9 @@ mu_cfg_tree_reduce (mu_cfg_tree_t *parse_tree,
       mu_stream_destroy (&stream);
     }
 
-  if (root_container)
-    {
-      struct mu_cfg_cont *cont = mu_build_container (progparam);
-      rc = mu_cfg_scan_tree (parse_tree, &cont->v.section, target_ptr,
-                             NULL);
-      mu_config_destroy_container (&cont);
-    }
+  cont = mu_build_container (progparam);
+  rc = mu_cfg_scan_tree (parse_tree, &cont->v.section, target_ptr, NULL);
+  mu_config_destroy_container (&cont);
 
   return rc;
 }
diff --git a/libmailutils/cfg/lexer.l b/libmailutils/cfg/lexer.l
index 40598a1a2..b6c49ecc1 100644
--- a/libmailutils/cfg/lexer.l
+++ b/libmailutils/cfg/lexer.l
@@ -330,10 +330,16 @@ mu_cfg_parse_file (mu_cfg_tree_t **return_tree, const char *file, int flags)
   int rc;
   char *full_name = mu_tilde_expansion (file, MU_HIERARCHY_DELIMITER, NULL);
 
+  if (flags & MU_PARSE_CONFIG_VERBOSE)
+    mu_diag_output (MU_DIAG_INFO, _("opening configuration file %s"),
+                    full_name);
   if (stat (full_name, &st))
     {
       if (errno != ENOENT)
         mu_error (_("cannot stat `%s': %s"), full_name, mu_strerror (errno));
+      else if (flags & MU_PARSE_CONFIG_VERBOSE)
+        mu_diag_output (MU_DIAG_INFO, _("configuration file %s doesn't exist"),
+                        full_name);
       free (full_name);
       return ENOENT;
     }
diff --git a/libmailutils/cfg/parser.y b/libmailutils/cfg/parser.y
index e36b513b0..043f7e0c7 100644
--- a/libmailutils/cfg/parser.y
+++ b/libmailutils/cfg/parser.y
@@ -1589,7 +1589,10 @@ mu_cfg_parse_config (mu_cfg_tree_t **ptree, struct mu_cfg_parse_hints *hints)
           mu_cfg_tree_union (&tree, &tmp);
         }
     }
-  
+
+  if (hints->append_tree)
+    mu_cfg_tree_union (&tree, &hints->append_tree);
+
   *ptree = tree;
   return rc;
 }
diff --git a/libmailutils/cli/Makefile.am b/libmailutils/cli/Makefile.am
new file mode 100644
index 000000000..48770e844
--- /dev/null
+++ b/libmailutils/cli/Makefile.am
@@ -0,0 +1,26 @@
+# GNU Mailutils -- a suite of utilities for electronic mail
+# Copyright (C) 2016 Free Software Foundation, Inc.
+#
+# This library is free software; you can redistribute it and/or
+# modify it under the terms of the GNU Lesser General Public
+# License as published by the Free Software Foundation; either
+# version 3 of the License, or (at your option) any later version.
+#
+# This library is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+# Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General
+# Public License along with this library.  If not, see
+# <http://www.gnu.org/licenses/>.
+
+noinst_LTLIBRARIES = libcli.la
+
+libcli_la_SOURCES = \
+ capa.c\
+ cli.c\
+ stdcapa.c
+
+AM_CPPFLAGS = \
+  @MU_LIB_COMMON_INCLUDES@ -I/libmailutils
diff --git a/libmailutils/cli/capa.c b/libmailutils/cli/capa.c
new file mode 100644
index 000000000..bd5c557e9
--- /dev/null
+++ b/libmailutils/cli/capa.c
@@ -0,0 +1,96 @@
+/* capa.c -- CLI capabilities for GNU Mailutils
+   Copyright (C) 2016 Free Software Foundation, Inc.
+
+   GNU Mailutils is free software; you can redistribute it and/or
+   modify it under the terms of the GNU General Public License as
+   published by the Free Software Foundation; either version 3, or (at
+   your option) any later version.
+
+   GNU Mailutils is distributed in the hope that it will be useful, but
+   WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with GNU Mailutils.  If not, see <http://www.gnu.org/licenses/>.
+*/
+#ifdef HAVE_CONFIG_H
+# include <config.h>
+#endif
+#include <stdlib.h>
+#include <string.h>
+#include <mailutils/cli.h>
+#include <mailutils/list.h>
+#include <mailutils/alloc.h>
+#include <mailutils/nls.h>
+
+static mu_list_t capa_list;
+
+static void
+capa_free (void *ptr)
+{
+  struct mu_cli_capa *cp = ptr;
+  free (cp->name);
+  free (cp);
+}   
+
+void
+mu_cli_capa_register (struct mu_cli_capa *capa)
+{
+  struct mu_cli_capa *cp = mu_alloc (sizeof (*cp));
+  cp->name = mu_strdup (capa->name);
+  cp->opt = capa->opt;
+  cp->cfg = capa->cfg;
+  cp->parser = capa->parser;
+  cp->commit = capa->commit;
+  if (!capa_list)
+    {
+      mu_list_create (&capa_list);