New vtkMEDStentModelSource with new stent models.
Hui version merged with Nigel version.
vtkMEDStentModelSource has been tidied, eg m_ on member variables,
no public member variables, more whitespace
and .h placed in #ifndef... #endif.

Changed .txx file back to _Impl.h.
Merge branch 'OpenMAF-2-2' of https://github.com/b3c/MAF2Medical into OpenMAF-2-2