NiFTK: No Functional Change: Tidy up Code/Libs/VTK and tests
By which I mean:
- File naming consistent
- Tidy up comments, read through them, check I understand them.
- Make unit tests have consistent naming.
VTK stuff does not have a namespace, but in library VTKNiftyReg we specify namespace niftk. This is one library where we can relatively easily add niftk namespace and hence niftk filename prefix.
Im aiming for one little tidy up at a time, when I get the time.