Bug 1023179  - Fix video unloading/loading, refactor initialization

Refactor of initialization sequence, logging to track down media loading issue
Why dont we listen `canplay`[1] event? `loadeddata` [2] is listening just the fist frame. Actually if we want to ensure that the video is completely loaded, we should use  `canplaythrough` [3]

[1] https://developer.mozilla.org/en-US/docs/Web/Reference/Events/canplay
[2] https://developer.mozilla.org/en-US/docs/Web/Reference/Events/loadeddata
[3] https://developer.mozilla.org/en-US/docs/Web/Reference/Events/canplaythrough