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
Things compile and the test-suite passes. Still need to hook up
gio.symbols and docs. There are still a bunch of TODOs left in the
sources that needs to be addressed.
Signed-off-by: David Zeuthen <davidz@redhat.com>