added thumbnail
adds support for changeMedia against mediaProxy override. 

* support thumbnail override for scrubber
Conflicts:
	kWidget/kWidget.js
	modules/KalturaSupport/components/scrubber.js
FEC-2327 close screens on change media

Conflicts:
	modules/KalturaSupport/resources/mw.KBaseScreen.js
removed api index prefixes; added example of changeMedia with mediaProxy
Conflicts:
	docs/content_api.php
* added empty player mediaProxy override example. 

* remove timeout for changeMedia ( slowing player build out )
* Check kalturaPlayerMetaData instead of entry id for "empty" player
Conflicts:
	docs/content_api.php
	modules/EmbedPlayer/resources/mw.EmbedPlayer.js
	modules/KalturaSupport/resources/mw.KWidgetSupport.js
removed unused method handleMediaProxyOverride
added support for cuePoints in stand alone player mode
Conflicts:
	modules/EmbedPlayer/EmbedPlayer.php