Add tooltips to bar charts

Add a class to format and populate tooltips from graph data sets and implement
those tooltips in the ChartController.
Add documentation for bar chart tooltips
Add jQuery tooltips
Rename tipsy stylesheet file type to css and add license
Add minified version of tipsy sources
Add information about the source and installation of all needed jquery-tipsy files
Merge branch 'master' into feature/svg-chart-tooltips-7024
Merge branch 'feature/svg-chart-tooltips-7024'