[Development] New qt5.6 beta snapshot available

[Tim Blechmann]

> These aren't yet final beta packages but please test these & report all
> new blocker immediately

no new blockers, but i still need to apply these two patches to be able
to compile 5.6-beta on osx:

https://codereview.qt-project.org/#/c/139577/
https://codereview.qt-project.org/#/c/139981/

both issues are compile failures for statically linked qt, though for
some reasons gerrit cannot integrate them.

--

btw, would it be possible to configure gerrit to build statically linked
qt and possibly also namespaced qt before integrating a patch? in the
past it happened quite often that those two configuration options did
not compile ... though this is all something which could easily be
verified automatically ...

cheers,
tim