Allow a title bar to be resized smaller than its width.

If a title bar becomes smaller than its width (the sum of widths of all its
icons) use an extension button to show hidden buttons.
Note that the title bar is as small as before but there is some space
between the title bar and the extension menu (when that appears).
It seems this is because the tool bar wants to be a certain size.

Change-Id: I53a019505937462c8aba20edb5c17df720a19e9e
Fixed some typos in documentation

Change-Id: Ie674381ca9ec9fda5ebb21afc6cac8b4bc49fcd3
Added advanced color and opacity map controls

These controls are tables that display the scalar values and assigned
colors and opacities for the current color and opacity maps,
respectively. Colors and opacities are limited to the range [0, 1].
Colors are specified as RGB triplets. The first and last scalar values
cannot be modified through the table as these are set via different
controls.

In addition, tabular formatted text data can be pasted from the
clipboard using Ctrl-V. The tabular text data must be delimited with
an arbitrary amount of whitespace (no newlines allowed). Pasting
always begins from the upper left to the bottom right table cells.

Change-Id: I2c10c9306d7e98c45cc37cec2ac16683876182f9
Merge topic '14383-manual-tfer-function-control-points' into next

34412a6 Added advanced color and opacity map controls
c4a38ed Fixed some typos in documentation
Remove vtkSESAMEReader.

vtkSESAMEReader is not used by Prism, we have new class vtkPrismSESAMEReader for
it.

Change-Id: Ia973ca9e4b026da30bef96de191abc7129e6943b
Merge topic 'remove_sesame_reader' into next

36a27bb Remove vtkSESAMEReader.
Merge topic '14368-toolbar' into next

2be288f Allow a title bar to be resized smaller than its width.