Merge pull request #25 from zotya/master

Added unpivot feature
Updated HISTORY.txt
Merge branch 'master' of https://github.com/collective/eea.googlecharts
Fixed jslints
Refs #17190; Added date type for pivoted columns
Prepare eea.googlecharts 9.2.
Updated version for eea.googlecharts to 9.3-dev
Added eea.icons as dependency for eea.googlecharts
Refs #17088; Fixed order of columns when using columnfilters
Refs #17088; Fixed order of columns when using pre-pivot filters
Adding Sphinx-generated documentation (refs #9502)

* adding documentation folder; contents are generated by the eea.github.com package
* registering ./documentation resourceDirectory as <package.name>.documentation
Refs #17087; Added resize for radar charts, fixed type icon for daviz tabs
Updating documentation to define 'here'
Refs #17087; Added png export for radar charts
Fixed typo
Pylint fix
Refs #18064; updated eea.googlecharts documentation after docs rebuild
Prepare eea.googlecharts 9.3.
Updated version for eea.googlecharts to 9.4-dev
Refs #18108; Don't show main column label in pivoted column labels