Add a dendrogram for the columns of the heatmap

vtkTreeHeatmapItem now supports a dendrogram for the columns of the
heatmap.  This provides users with a way to interactively collapse
and expand columns.

The GetBounds() methods of vtkDendrogram, vtkHeatmapItem, and
vtkTreeHeatmapItem now include the size of any displayed text labels.
This required some changes to the way that the components of
vtkTanglegramItem are laid out.

Change-Id: Icdc9342d360b772819ff7863ed2a971e8865003e
add test for column trees

Add a test for the new column tree functionality of
vtkTreeHeatmapItem.

This commit also updates the test for vtkTanglegramItem.  The
appearance of this item has changed now that column labels are
included in the values returned by GetBounds().

Change-Id: I36b8383533d9c61db81e47df278d34577d6ddbeb
Merge topic 'hardware-selector-pv-bug' into pv-master

05c3c42 Merge topic 'hardware-selector-pv-bug' into master
0fb0db0 BUG: Un-hide overlaoded functions in vtkOpenGLHardwareSelector
65149ed Merge topic 'charts-windows-baselines' into master
f658d14 Merge topic 'hardware-selector-pv-bug' into master
39a97ad Added baselines for Windows double precision charts
9921794 Merge topic 'fix_win_python_static_comp_warning' into master
8fff4d9 Merge topic 'web-reorder-warning' into master
8e0a977 Fix "reorder" warning about Scroll member.
503d68d refactor vtkHardwareSelector device state management
d65607e fix symbol import/export warning on windows static python dashboard
Merge topic 'update_vtk_master' into pv-master

28c708e Merge topic 'update-kwsys' into master
063fb58 Merge topic 'vtkweb-add-file-widgets' into master
7087e30 Add server side FileBrowser
a9d18cd Merge topic 'remove-range-wrapping' into master
df94b85 Remove range[2] overloads for vtk*DataArray wrappings
b1841bf Merge topic 'vector-parameter-wrapping-support' into master
f13ab5c Merge topic 'context2d-private-deps' into master
8d32385 Merge topic 'StructuredData-GetLinearIndex' into master
3c2603d Merge topic 'amd-radeon-hd-depth-peeling' into master
a9db3e2 fix bug14192: ProbeFilter can't probe an Image with more than 2^31 cells
8f4f560 Cleanup warning of shadow variable in vtkDepthPeelingPass
f76cf15 Merge topic 'amd-radeon-hd-depth-peeling' into master
3f6e7bc Merge topic 'TanglegramFixForVtkWeb' into master
59da79c BUG: Use smart pointer for table in vtKTanglegramItem.
3f3fc91 Merge topic 'no_weights_tree' into master
8c418bc Merge topic 'handle-null-whole-extent' into master
...
Merge remote-tracking branch 'pvvtk/pv-master' into HEAD

* pvvtk/pv-master:

Change-Id: I64da9794a7fdba22143d752699a4cf675c8b34b7
Merge topic 'collapse_columns' into master

8c716e6d add test for column trees
728192ea Add a dendrogram for the columns of the heatmap
COMP: Fixed unused variable warnings in tests
COMP: Disable tests since paths are set wrong in VTK
Extend vtkWeb with basic properties and improve File browser

Change-Id: Iad350ca42639da1f0ebde22516f78c48a8c84845
Merge topic 'vtkweb-update-file-browser' into master

80edc282 Extend vtkWeb with basic properties and improve File browser