Bug fixes

Inject rtl content script for *://rtlxl.nl/*
Fixed javascript errors when no video was selected on RTL XL
Fix episode switching for Uitzending Gemist with HTML5 enabled (when
selecting items from the "Other episodes" list)
Mark current episode in "Other episodes" list when using HTML5 player
Decreased interval check interval to every second to make the download
button appear faster after selecting an episode
Merge branch 'pr/3'
New extension name