giomodule: Fix leaks in module loading

https://bugzilla.gnome.org/show_bug.cgi?id=711798
enums: Fix leaks in tests

https://bugzilla.gnome.org/show_bug.cgi?id=711779
threadtests: Fix leaks in tests

https://bugzilla.gnome.org/show_bug.cgi?id=711779
accumulator: Fix leak in test

https://bugzilla.gnome.org/show_bug.cgi?id=711779
gvalue-test: Fix leaks in test

https://bugzilla.gnome.org/show_bug.cgi?id=711779
override: Fix leaks in test

https://bugzilla.gnome.org/show_bug.cgi?id=711779
paramspec-test: Fix leaks in tests

https://bugzilla.gnome.org/show_bug.cgi?id=711779
signals: Fix leak in test

https://bugzilla.gnome.org/show_bug.cgi?id=711779
timeloop-closure: Fix leaks in test

https://bugzilla.gnome.org/show_bug.cgi?id=711779
defaultiface: Fix leak in test

https://bugzilla.gnome.org/show_bug.cgi?id=711779