Added a new rendering test to better illustrate a lookuptable and the corresponding rendering mode.
Fixed Thresholding for float images.

There were some casts to integer for the slider values. So in case of an
image with values < 1.0 this led to wrong results. Also for thresholding
by itk filter the pixel type was set to int.
Fix for 4D images.
Merge branch 'bug-15763-move-classes-into-new-module' into bug-16006-ContourModelSet
Added container class.
Merge remote-tracking branch 'origin/bug-15763-move-classes-into-new-module' into bug-16006-ContourModelSet

Conflicts:
	Modules/SegmentationContour/Testing/files.cmake
Fixed parameter types.
Inherit from BaseData.
GL based ContourModelSet mapper.
2D mapper.
Merge branch 'bug-16006-ContourModelSet' into bug-16006-ContourModelSet-integration

Conflicts:
	Modules/ContourModel/Rendering/mitkContourModelGLMapper2D.h
Move classes to renamed ContourModel folder.
Use ContourModel_EXPORT.
Added 3D mapper for ContourModelSet.
Added 3D mapper for ContourModelSet.
Merge branch 'bug-16006-ContourModelSet-integration' of mitk.org:MITK into bug-16006-ContourModelSet-integration
New files
IO classes
Fix increment iterator
Initialize ContourModelSet