[CDF-287] - As a user, I want to be able to define a chart made up of arbitrary, compatible, plots.
* Fix legend API returning stale values right after execute.
[CDF-287] - As a user, I want to be able to define a chart made up of arbitrary, compatible, plots.
* Unified the "logical group" concept between the relational and crosstab translator classes.
* Fix plot2SeriesIndexes (and population of the dataPart dimension) not being taken account in charts having custom translation mixins.
Merge pull request #102 from dcleao/CDF-287

[CDF-287] - As a user, I want to be able to define a chart made up of arbitrary, compatible, plots.