Fixed warnings.

Change-Id: I8e17c9a528d400d67eedae2ea2d5b7eb0c5e03ae
Merge topic 'visible_range' into next

bc4a394a Fixed warnings.
Minor code restructuring for consistency.

Moving the method to rescalate LUT to visible range to
vtkSMPVRepresentationProxy from vtkSMTransferFunctionProxy.

Moving ExtractSelectionRange to "internal_filters".

Change-Id: I6a734d20b146497ba74e59e8875ec3db19316b77
Adding test to test resetting to visible range.

Change-Id: Ib4ec7037fe8d894805db33c0dddaeb3a69956d7e
Merge topic 'visible_range' into next

30ec5eb0 Adding test to test resetting to visible range.
c161dd14 Minor code restructuring for consistency.