Restructuring of the vtkSMParaViewPipelineController API.

Restructured the vtkSMParaViewPipelineController API to be easier to
understand and use. The aim was to make it more obvious which methods
register the proxy.

Change-Id: Iead555bc4e39816b1252f55e2650f4d221223ac5
WIP: Updating Python.

Also moved SurfaceRepresentationBase to "internal_representations" since
otherwise we were getting warning messages as the representation
prototypes were being constructed.

Change-Id: I3903ae827907d2b2c0ea23ec01fa69bcadc31b31
WIP: Working on fixing global properties.

Change-Id: I577d7d12a4a02a550535dc963759d68e827964ff