examples: fix compilation of gl fxtest example on win32 with Gtk+ 3.0

https://bugzilla.gnome.org/show_bug.cgi?id=733063
wrappercamerabinsrc: set src to ready when there are no pending buffers

Setting to ready will block waiting for buffers to be reclaimed, so flush
before setting to null to make sure no buffers are pending

https://bugzilla.gnome.org/show_bug.cgi?id=733072
po: Update translations
Update .po files
Release 1.4.0
Back to development
watchdog: Add unit test

And improve some debug prints