ENH: Update selected Filters/General to support DesiredOutputPrecision

This is first of several commits updating filters to support a choice
of desired precision (default, single, or double) for output points. It
uses the analogous code in vtkThreshold as a model.

Change-Id: I7b87d126d9015b8e1ed2ece2368b866147d8c124
ENH: Update selected Filters/Sources to support DesiredOutputPrecision

This updates selected sources to support a choice of desired precision
(single or double) for output points. It uses the analogous code in
vtkThreshold as a model.

Change-Id: If616db48b3d979b7ac01d3b5200fff523b06a26b
ENH: Update vtkProcrustesAlignmentFilter to support DesiredOutputPrecision

This updates vtkProcrustesAlignmentFilter to support a choice of
desired precision (default, single, or double) for output points. It
uses the analogous code in vtkThreshold as a model.

Change-Id: Iaf82e72089b95a1787701b3d9ae7a6c4116c01a5
Merge topic 'pvweb-file-loader-with-group' into pv-master

742e705 Extend Web file browser to support file grouping
80fa7c3 Merge remote-tracking branch 'pvvtk/pv-master' into HEAD
df005bf Merge topic 'vtkweb-prevent-webgl-error' into master
31ae28c Make sure if Webgl trigger exception it won't prevent other modules to load
ebcf6e2 Merge topic 'amd-projected-tetra' into master
60fbcda ati projected tetra bugs
189c4eb Merge topic 'fix_extract_cth_filter' into master
0337035 Merge topic 'set_tree_edge_width' into master
ad2e7b1 Merge topic 'ffmpeg-update' into master
5b39c91 Updates to the FFMPEG code, modernizing and improving
b75988f Merge topic 'doxygen-configured-files' into master
52c0f0e Merge topic 'fixed-smp-warnings-order' into master
9b1b716 Merge topic 'fix-smp-empty-input' into master
a4718ce Fixed warning about initializing variables in right order.
3e73e29 Fixed empty input bugs in SMP filters.
9362f06 Merge remote-tracking branch 'pvvtk/pv-master' into HEAD
...
Merge remote-tracking branch 'pvvtk/pv-master' into HEAD

* pvvtk/pv-master:

Change-Id: I3029208f8bd1835bde2d31bff27a2dedf0a937bb
Merge topic 'filters-general-desired-output-precision' into master

6025498d ENH: Update selected Filters/General to support DesiredOutputPrecision
Merge topic 'filters-sources-desired-output-precision' into master

28976fd3 ENH: Update selected Filters/Sources to support DesiredOutputPrecision
Merge topic 'procrustes-alignment-desired-output-precision' into master

716436e8 ENH: Update vtkProcrustesAlignmentFilter to support DesiredOutputPrecision