[CDF-287] - As a user, I want to be able to define a chart made up of arbitrary, compatible, plots.
* More changes to site examples. A new Pie multiple plot example.
* New pvc.finished helper function to make it easier to specify "finished" extension points.
[CDF-287] - As a user, I want to be able to define a chart made up of arbitrary, compatible, plots.
* Support for absolute extension prefixes in pvc_unwrapExtensionOne
* New helper function to generate random extension prefixes
[CDF-287] - As a user, I want to be able to define a chart made up of arbitrary, compatible, plots.
* Fix Pie plot multi-line linked labels being too close.
[CDF-287] - As a user, I want to be able to define a chart made up of arbitrary, compatible, plots.
* Documentation rewording, regarding legend options.
[CDF-287] - As a user, I want to be able to define a chart made up of arbitrary, compatible, plots.
* Small change to be able to reuse a variable.
[CDF-287] - As a user, I want to be able to define a chart made up of arbitrary, compatible, plots.
* Removed legacy/stale "hidden" def on the legend panel. Added the ability to hide individual items through extension point. No layout reflow though between sections.
[CDF-287] - As a user, I want to be able to define a chart made up of arbitrary, compatible, plots.
* A few file renames of files that weren't following the normal naming.
* Refactored the legend renderer classes.
* Removed "bullet" from the legend-related names.
* Changed the structure of legend scenes; now not following the one group per color axis and data cell rule; now, one color axis means one legend group; within the same legend group, multiple data cells may be present and each corresponding plot panel may register a legend symbol renderer.
* Visibility of the legend of a data cell is controlled by the corresponding visual role's "legend.visible" option.
* Legend symbol extension points can now be unambiguously specified in the color visual role's legend option object. This substitutes the existing "legend" + index, which are hard to know the indexes of; compatibility was maintained;
* Locking of legend items containing only trend datums, when in visibility clickMode, is now handled by the LegendItemSceneVisibility mixin.
* Added the ibits method to pvc.Interactive so that implementations may lazily calculate it; this was required to support the ability to not hide the last visible legend item.
* Updated unit tests relating to visual role's legend options.