Site: Styling documentation for the currently provided three CSS
framework integrations:
        - Bootstrap
        - Foundation
	- jQuery UI
Fix: DT_RowClass wasn't being updated when modified in the data source.

- This is actually a little more complex than it might first appear
  since any classes which have been added by DT_RowClass need to be
  removed. We can't just bindly remove all classes, so we need to track
  that classes have been added in a private variable.