Code review comment for lp:~ted/indicator-appmenu/hud

More meddling after reading larsu's great review:

 * g_clear_object() could be used in a couple of places in indicator_tracker_dispose() and dbusmenu_collector_dispose(). (Thanks larsu! I didn't know about that function either ;)

 * as per larsu and awe's questions about NULLing out the priv fields right before assigning them... maybe a memset (priv, 0, sizeof(Priv)) would be better idiom. It's only 1 loc, of course, but more importantly, it makes clear the intent of unconditionally zeroing everything.

 * several files include both glib.h and glib-object.h:
     _ dbusmenu-collector.h
     _ distance.c
     _ hud-dbus.h
     _ hud-search.h
     _ hud-verify-app-info.c
     _ indicator-tracker.h
     _ usage-traacker.h
     _ window-menus.h

 * several files have the redundant declarations of _init and _class_init after G_DEFINE_TYPE
     _ dbusmenu-collector.c
     _ hud-dbus.c,
     _ hud-search.c,
     _ indicator-appmenu.c (twice)
     _ indicator-tracker.c
     _ usage-tracker.c
     _ window-menus.c