The apple build was broken because the elseif in the CMakeLists is never triggered.
Some code was not properly adapted for the new qtmacgoodies.
Some paths were not adapted to new split.
This implements out-of-repository-theming, and removes the old
custom.ini theming that never worked on all platforms and had
no straight deployment story.
The new approach requires the CMAKE variable OEM_THEME_DIR to
point to a directory that must at least contain an OEM.cmake file
(check OWNCLOUD.cmake for possible options) as well as a themes.qrc
and a themes/ directory that directly correspond to the ones in
the source tree.
