Since bug #745728 was fixed the oldest supported version of GStreamer is
1.2. That GStreamer release requires glib 2.32, so we can upgrade our
requirement too.
This patch changes the required version of glib in configure.ac and removes
the hacks in glibcompat.h
https://bugzilla.gnome.org/show_bug.cgi?id=748698
g_async_queue_timeout_pop() appeared in glib 2.31.18. Implement it as
g_async_queue_timed_pop() with a GTimeVal as the final time to wait for
new data to arrive in the queue.
This is a preferred thread-safe version. Also add an inline version of
g_clear_object() if compiling with glib < 2.28.
Signed-off-by: Gwenole Beauchesne <gwenole.beauchesne@intel.com>