Provide keyboard support for the MediaPlayer.

Some of the occurring problems are:

• It is not clear how to get focus on the control, we assigned an accesskey="T" but  alt-t doesn't give focus (we have  a radmenu on the same page with an accesskey="M" which works fine)
• The tab key sometimes does not work.

Keyboard navigation is required for 508 accessibility support. Generally the space bar is used to start/stop video and tabs are used to access the playbar features like expand, vol and CC