Remove g_type_init() calls

Very many testcases, some GLib tools (resource compiler, etc) and
GApplication were calling g_type_init().

Remove those uses, as they are no longer required.

https://bugzilla.gnome.org/show_bug.cgi?id=686161

gio/tests/async-close-output-stream.c

@@ -247,8 +247,6 @@ main (int   argc,
 {
   SetupData *data;
 
-  g_type_init ();
-
   g_test_init (&argc, &argv, NULL);
 
   g_test_bug_base ("http://bugzilla.gnome.org/");