Cleanup Python sys.path setup in ParaView.

Cleaning up the logic to setup Python sys.path for build and install locations
for all supported platforms. This refactoring makes it easier to update and
correct paths, if needed, in future versions.

Change-Id: I4d818331d0cfb3c07e823c26dc95054adbaa89f0
ParaView binaries weren't using packaged Python.

The problem was that the Py_SetProgramName() wasn't being called when expected.
That was resulting in Python not trying to look for Python packaged with
ParaView and hence the binaries were failing. This should fix that problem.

Change-Id: I704edd1c6443422cba3b5a2b4bddbef5a3509365
Merge topic '14054_slice_crinkle_bug' into next

9b49310 Move VTK forward to get vtkExtractGeometry fix
Merge topic '14072_splash_default_off' into next

4b22b63 Change the behavior for splash screen, default off.
Merge topic '14075_coprocessing_script_generator' into next

899be38 Allowing co-processing scripts to be generated when nothing is outputted.
0131c16 Getting rid of annoying trailing white space.
Merge topic 'fix_python_paths' into next

11e32d1 ParaView binaries weren't using packaged Python.
cd77d5c Cleanup Python sys.path setup in ParaView.