Fix link error.

The `CoProcessingPythonScriptExample` executable is not getting linked
due to a missing `vtkRenderingMatplotlib` dependency added to the list
of VTK modules when bringing in categorical color support. Explicitly
add the library as a dependency if it exists.

Change-Id: I9f08be9dbc2cac62fa8ee49de364975684ee5454
Fix random warning showing up on the dashboard

Change-Id: Ic9fbedcf3609eabc16bee119cf01908a523ea9d7
Couple more warning fix

Change-Id: I569fb9ef537f9bec02369c4ac1db77f9f2d0172f
Forward VTK to bring in 'fix-glsl-shader-device-adaptor2'

Change-Id: Iab0d831d1aafd7b34d7a52b8125755a1f45c75df
Change Matplotlib test to avoid console output.

Change-Id: Ied842cffc974f9bc1eee5c546a3951424c0c97a2
Update VTK to VTK/master.

Change-Id: I1ca989b0c8b310521ea9f76a7dda43eac855dc22
Don't erase existing annotations for empty preset.

Change-Id: I8533d10790ac2aa3faab9b9f46f893a3805ba3fd
Use data values for annotations when preset empty.

Change-Id: I1598b1a7556e698f51300414c2e510b5508adeb7
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
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 'categorical-colors-fixes'

a228551 Fix link error.
Merge topic 'chart-selection-representation'

3523511 Refactoring SelectionRepresentation for charts.
899fac3 Fix ResetDisplay for charts.
Merge topic 'color-preset-annotation-tweak'

a52bdc6 Use data values for annotations when preset empty.
e57cb5e Don't erase existing annotations for empty preset.
Merge topic 'command-button-property-widget'

367eed8 Add command button property widget
Merge topic 'fix-glsl-shader-device-adaptor2'

a53c26a Forward VTK to bring in 'fix-glsl-shader-device-adaptor2'
Merge topic 'fix_plugins_warnings'

012459a Couple more warning fix
b5067f9 Fix random warning showing up on the dashboard
Merge topic 'matplotlib-detection-tweak'

051dc3e Change Matplotlib test to avoid console output.
Merge topic 'update_vtk_master'

455d0b2 Update VTK to VTK/master.