RichText editor event tear down fix
Event handles generated in the onLoad function of RichText were not being 'owned' properly. I updated the mapper to return a list of handles instead of undefineds and created a handle passed to own that would call remove on each of the event handles

Added test to show RichText is no longer throwing errors when being destroyed

Simplified fix as per wkeese, re-ran tests, every still appears to be working