Show start time or starting position on slider and VCR.

When the start time is set, or a initial position is
set,the VCR timer and the time slider should jump to
correct starting point before the video starts playing.

BLD-823
Added Jasmine test.
Addressing jmclaus, and polesye comments.
Fixing falling Jasmine test.
Removing unnecessary complications.

In Jasmine tests, YouTube player is fully mocked. No need
to make tests passable in various browsers due to the fact
that real YouTube API acts differently in different browsers.
Addressing polesye comments.

Adding more Jasmine tests.
Fix unit tests.