Update ConvertCueToDOMTree() to return a div.

The specification says that we should return a 'transparent
positioned CSS block box'. A plain div will do fine for this.
This also ensures that we can add CSS to the top level div.
Merge pull request #90 from RickEyre/div-fix

Update ConvertCueToDOMTree() to return a div.
Updated the lang tests with correct utf-8

Also wired tests into the test harness