Merge topic '14741_proxies_widget'

fd56e07a Adding a mechanism to create a proxy widget for several proxies.
Merge topic 'FixFunctionalBagPlots'

7b7a6621 Fix and enhance functional bag plots.
Merge topic 'discretize_color'

0ce9fad4 Make discretize color more prominent
Merge topic 'fix-install-test'

ff18672e test: don't overwrite the actual install when testing
Merge topic 'fix_catalyst_editions'

e31e78a4 Use correct options/process type for catalyst tests.
aff5b1fe Fix issues with Catalyst editions.
ba6d98e7 Move TimeKeeper proxy definition to base.
Merge topic 'fix_osx_test_issues'

0c935965 Fix Sphinx documentation.
47198123 Fixed checks for drawable when rendering.
Merge topic 'rescale_custom_range'

cd60f685 Add shortcut button rescale custom range
Merge topic 'update-protobuf'

b1c92065 Update protobuf module to get fix for CMake 3.0
Merge master into next

* commit 'aa525d5d662ea6c7036e47a07e4c8a146a773e5f':

Change-Id: I4bca1d725f24e02223f19bdfbe537f82a3ce4c74
Merge topic '14742_vtkImageDataToUniformGrid' into next

44e7bf41 Updating XML definition of vtkImageDataToUniformGrid filter.