Added GroupTab extensions
Webui: grouptabpanel applied
Webui: added bubble extension
Webui: bubble app header
Webui: renamed dvr and epg panel title

Conflicts:
	src/webui/static/app/epg.js
Webui: extensions: added missing images + fixed missing theme s.gif
Webui: reverted default theme for testing purpose
Webui: changed to .png all image refs in default theme's css
Webui: tabs padding
Webui: restored panel border
Webui: main panels borders look