qt: upgrade to 5.3.2

This commit also removes the 5.2 branch in favor of 5.3. Several
components of KDE5 require Qt 5.3, so it doesn't make much sense to have
the rest of the system on an older version. Also, the application styles
may not be compatible because Qt breaks ABI compatibility between versions.
polkit-qt-1: Qt 5 support

polkit-qt-1 is upgraded to the latest version, which supports Qt 5. The
attributes are also renamed to differentiate the Qt 4 and Qt 5
branches. The prior naming scheme differentiated between polkit-qt-1 and
polkit-qt, but we no longer package the latter.
phonon: upgrade to 4.8.1

This version adds Qt 5 support.
phonon-backend-gstreamer: add Qt 5 support
phonon-backend-vlc: add Qt 5 support
qt5: find timezone table in $TZDIR
Merge branch 'qt5-support' into staging

Update Qt 5 to version 5.3.2. Drop the 5.2 branch. Update several
libraries to their latest versions to take advantage of Qt 5
support. The last point will cause a KDE 4 rebuild.
Merge branch 'qt5-tzdir' into staging

Fixes a long-standing bug with Qt 5 and timezones on NixOS.