Add files, and made modifications for MatlabMex to wotk in vtk 6

reverting include of assert.h to cassert

modified module to be stand alone, toggled using an advanced options VTK_USE_MATLAB_MEX

modified as Mr. Hanwell directed.  Removed groups completely.  Thanks for the help.

Change-Id: I1dd28354aa70cabbf34c978517ea0f6b4ed6aed7
Merge topic 'fix-matlabmex' into master

eec6db36 Add files, and made modifications for MatlabMex to wotk in vtk 6