switch to bitbucket repo, add pyObjC for osxmmkey

Building quodlibet from hg requires a patch to jhbuild
to support going to the quodlibet subdirectory.
It's also not possible to select a branch or a revision.
move quodlibet icon aside
exfalso bundle

It is intended to run after gtk-mac-bundler quodlibet.bundle && ./postproc.sh
as it copies most of the files from Quodlibet.app.