Added g_type_init for older glib versions

Hello!

g_type_init is deprecated in Glib since 2.36, but is needed for older versions. Without this init call, the program will crash with following error message: 

GLib-GObject 2013-07-28 00:36:35 [CRIT] /build/glib2.0-AWe8Zn/glib2.0-2.33.12+really2.32.4/./gobject/gtype.c:2722: You forgot to call g_type_init()
GLib 2013-07-28 00:36:35 [CRIT] g_once_init_leave: assertion `result != 0' failed
GLib-GObject 2013-07-28 00:36:35 [CRIT] g_object_new: assertion `G_TYPE_IS_OBJECT (object_type)' failed

I dont know if you want to support older versions of 3pp's, but the Wheezy packages comes with an older version. 
http://packages.debian.org/wheezy/libglib2.0-0