Implement shutdown components

* src/pies.h: Update comment.
* src/progman.c (register_prog0): Register shutdown components
in disabled state.
(program_shutdown): New function.
(progman_stop): Call program_shutdown.

* tests/shutdown.at: New test.
* tests/Makefile.am: Add new test.
* tests/testsuite.at: Likewise.
* tests/aux/startup: Rename to tests/aux/touchfile
* tests/startup.at: Reflect the change.

1 files changed, 7 insertions, 0 deletions

diff --git a/tests/aux/touchfile b/tests/aux/touchfile
new file mode 100755
index 0000000..b9d92a3
--- /dev/null
+++ b/tests/aux/touchfile
@@ -0,0 +1,7 @@
+#!/bin/sh
+dir=${1:?}
+time=${2:?}
+tag=${3:?}
+
+touch $dir/$tag
+sleep $time