Merge branch 'kcm2'

This implements a completely new version of the KScreen KCM, based on
usability research and advices from Bjoern and Heiko.

The UI has two parts: a QML-based view with monitors that can be dragged
around to reposition screens, and a widget-based part, that provides
detailed configuration for each screen, like resolution, rotation, etc.

Conflicts:
kcm/qml/OutputView.qml
kcm/src/fallbackcomponent.h
kcm/src/kcm_kscreen.cpp
kcm/src/kcm_kscreen.h
kcm/src/kcm_testapp.cpp
kcm/src/modesproxymodel.cpp
kcm/src/modesproxymodel.h
kcm/src/qmloutput.cpp
kcm/src/qmloutput.h
kcm/src/qmloutputcomponent.cpp
kcm/src/qmloutputcomponent.h
kcm/src/resolutionsortmodel.cpp