Add seek support

[PowerSlime]

Users should be able to synchronize their time with another users by seeking the video.

Main problem that kodik player doesn't have encessary events. I think, it is possible to add by watching set currentTime if abs(newTime - oldTime) > 1 then we got a seek event.

When we got it a socket message should be emited to let other users know our currentTime. It is possible by trigger player.seek(currentTime) by default it sends message to socket too.

[PowerSlime]

Shouldn't be abs(newTime - oldTime) > 1 we must handle backward seek. In that case it will not handle backward seek of 1 second