Fix ResetDisplay for charts.

Sometimes ResetDisplay would have no effect on charts. As soon as one interacted
with the chart and called ResetDisplay again, it would work. The problem was
that if the *AxisRange properties were already unset, then they would not be
pushed and hence the view would not reset the axis. This fixes that issue by
ensuring that the *AxisRange properties are pushed.
Refactoring SelectionRepresentation for charts.

Charts using the same representation (vtkChartRepresentation) to manage data as
well as selection. The problem with  this approach is that whenever the
selection changes, we have to reexecute the vtkChartRepresentation even if the
data didn't change and only the selection changed. The representations in 3D
view deal with this my creating a separate SelectionRepresentation and the
selection input is fed directly to this representation. That way when the
selection changes, only the SelectionRepresentation is modified. We adopt that
same approach for chart representations.

Added a new vtkChartSelectionRepresentation. vtkChartRepresentation now creates
a vtkChartSelectionRepresentation that deals with delivering/showing selections.
vtkSIChartRepresentationProxy ensures that the vtkChartSelectionRepresentation
is set correctly on the vtkChartRepresentation; while
vtkSMChartRepresentationProxy ensures that the selection-input is set correctly
on the proxy corresponding to vtkChartSelectionRepresentation.

+ Also cleaned up AnnotationLink. Now, we consistently create AnnotationLink in
the vtkPVContextView (or subclass). In the past the link was created in
vtkChartRepresentation or vtkPVPlotMatrixView.

+ Also cleaned up vtkPVCompositeRepresentation.

During the evolution of vtkPVCompositeRepresentation, there was stage when we
were thinking of passing selection-input transparently to the
SelectionRepresentation held by vtkPVCompositeRepresentation. However, that
meant that vtkPVCompositeRepresentation would be marked as modified whenever the
selection changed. So to avoid that, we changed the code to setup the selection
input directly to the SelectionRepresentation in vtkSMPVRepresentationProxy.
The unused code persisted in vtkPVCompositeRepresentation. Removing that.

Change-Id: I1c834976c1aeb6343732a3c61fb3bd4876562ff0
Merge topic 'chart-selection-representation' into next

3523511 Refactoring SelectionRepresentation for charts.
899fac3 Fix ResetDisplay for charts.
Fixed BUG #13491. Update array lists for statistics filters.

Added new pqArrayListDomain. pqArrayListDomain ensures that the arrays shown in
the varibles list for the statistics filters is updated whenever the domain
changes. The domain changes when user swicthes the attribute mode, for example.

Change-Id: Iea63d596a5f3a7bbf2a03325070cd2c4cc23f10f
Merge topic '13491_fix_statics_panel' into next

8e80797 Fixed BUG #13491. Update array lists for statistics filters.
Fixed comment.

Change-Id: I064ee330d50c468dde78af1c0380afd6750c471e
Merge topic '13491_fix_statics_panel' into next

643e9b4 Fixed comment.
Add command button property widget

This adds a new custom property widget which displays a button
on the properties panel and will invoke the property's command
when clicked.

For example:

  <Property name="New Instance Button"
            command="New"
            panel_widget="command_button">
  </Property>

Will show a button that when clicked will call the "New()" method
on the proxy.

Change-Id: Iba4a9af38670cff1e641dc0ba970b69a99adb229
Merge topic 'command-button-property-widget' into next

367eed8 Add command button property widget
BUG #13489. Bring in VisItBridge cmake fix.

Change-Id: I002b7b8f770caa034786b2b473d8173c79ae1539
Merge topic '13489_visit_bridge_os_mesa' into next

315f8de BUG #13489. Bring in VisItBridge cmake fix.
BUG #13475. Adding API to select/unselect cells.

Adding APU to select/unselect cells in Python. Users can now use SelectCells()
and ClearSelection() to make new selections from Python.

Change-Id: Idfda0824242de3f9617267215ea29cde7cbb4aaa
Merge topic '13475_add_select_cells_python_api' into next

06de226 BUG #13475. Adding API to select/unselect cells.
BUG #13488. Fixed XML loading order during initialization.

The XMLs were not loaded in the right order when auto-loaded plugins were
present. Fixed that. We need to process the xmls from vtkPVInitializerPlugin
before any other plugins.

Change-Id: I41af5ab6e68e33da9607023cf87a2b6b24e1b687
Merge topic '13488_fix_auto_load_plugins_issue' into next

9c1aad8 BUG #13488. Fixed XML loading order during initialization.
Making test more reliable across platforms.

Change-Id: I6dfc08e0c313f696341c04098f2c8c0a0b46bf22
Merge topic '13475_add_select_cells_python_api' into next

ce7f080 Making test more reliable across platforms.