BHV-11000: Make both src and sourceComponents in enyo.Video works

DCO-1.1-Signed-Off-By: Kunmyon Choi kunmyon.choi@lge.com
revised updateSource to allow it to be called from create()
fixes source selection post-create
adds sample to test changing video source
Merge pull request #795 from BHV-11000-kunmyonchoi-new