Remove legacy depth peeling support
introduce rendering mode in preference menu
Standard Rendering, Depth Peeling and Multi Sampling
Change in ContourMapper2DTest
restored former constructor and fix the initialize method
Merge branch 'bug-16746-depth-peeling' into bug-16746-integration-depth-peeling

Conflicts:
	Modules/QtWidgets/QmitkRenderWindow.cpp
made pointsetmapper2d indepedent from slicenavigationcontroller geometry
Set QLocal to English, because otherwise the local computer settings will be used (on a German Computer, there will be a commata instead of a point for decimals).

Wrong line endings changed the whole file, only new contribution is in line 224:
  QLocale::setDefault(QLocale(QLocale::English, QLocale::UnitedStates));
New test for depth peeling
Integrate batched registration
removed warnings.
Fix package dependencies in case of MITK_USE_QT = OFF.
Change logic for forcing of Qt dependent variables.
Merge branch 'bug-17452-fix-mitk-use-qt'
Update Qt minimum version to 4.7.
Merge branch 'bug-17523-update-qt47'
VS2013 compilation fixes
Compilation fix for VTK 6.0
Update superbuild to GDCM 2.4.1
Merge branch 'bug-17533-update-gdcm24' into bug-17376-vs1013-compatibility