New HTML-based TTML rendering not working on IE11

Created by: TobbeMobiTV

Subtitles are not rendered with the new HTML TTML (EBU-TT-D) rendering. Seems to be due to cue styling not supported, but since it is only used to remove a black line on Chrome from empty VTTCues, it should be able possible to disable the cue styling on IE11.

A fix should go into the 1.5 release.