Remove old HTML generation code from DisplayMediator
getDisplayable is no longer required, we still need to directly inject a modified version of DisplayMediator
DisplayableObject is no longer implementing Displayable
Fix some documentation. Annotate toHtml() with Deprecated.
Merge branch 'master' of https://github.com/Sanrag/groningen
Merge pull request #9 from Sanrag/master

Partial cleanup of DisplayMediator.