currentTime not reset for multiple loads

`player.currentTime` is not reset after a `player.load(...)` is called for the **2nd time**.

`player.playing` is true and the `player.currentTime` is set to the previous currentTime. This causes the progress bar to jump briefly before being set correctly.

Our current workaround is to:

``` javascript
// bug fix for player... reset currentTime to zero when track is 0
$scope.$watch("player.currentTrack", function(newVal,oldVal) {
if( newVal != oldVal && newVal === 0 && $scope.player.currentTime > 0) {
$scope.player.currentTime = 0;
}
});
```

Start by reproducing two consecutive player.load(...) calls while player.playing is true, then inspect the player state handling around currentTime and currentTrack. Compare the behavior with the workaround watcher shown in the issue; done means the progress bar does not briefly show the previous track position after the second load.

Written by the indexing model from the issue text.