[glibmm] Threads: Mark the doxygen module as deprecated.

[Murray Cumming <murrayc src gnome org>]

commit b7b8f2712a187ab5e22efd14338c1de6338b6746
Author: Murray Cumming <murrayc murrayc com>
Date:   Mon Nov 30 09:20:35 2015 +0100

    Threads: Mark the doxygen module as deprecated.

 glib/src/threads.hg |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)
---
diff --git a/glib/src/threads.hg b/glib/src/threads.hg
index 0dcaa49..51decfc 100644
--- a/glib/src/threads.hg
+++ b/glib/src/threads.hg
@@ -48,6 +48,9 @@ _GMMPROC_EXTRA_NAMESPACE(Threads)
 /** @defgroup Threads Threads
  * %Thread abstraction; including threads, different mutexes,
  * conditions and thread private data.
+ *
+ * @deprecated The entire Glib::Threads API is deprecated in favor of the
+ * standard C++ concurrency API in C++11 and C++14.
  * @{
  */