Changes to support Adapative streaming ( DASH/Smooth/HLS) in TAL

I have made some changes  in TAL to support DASH/Smooth/HLS  media playback.
Changes are in mediasource.js and samsung_maple.js.  

These are tested in 2013 Samsung and LG Smart TVs.  Also executed the test cases as give here http://fmtvp.github.io/tal/testing.html.