juggle methods and properties between player and app

Add property player.defaults with the webPlayer defaults.
Deeplink parsing is part of the app callback (and still WIP).
The error handler that tries to remedy the problem by removing media
files that might be unrecognised is still part of the player module as
the list of all registered players.
re-enable embedding module

Now, that resizing happens only on initial open of the metadata tabs
smooth transition is not an issue anymore.

TODO: stop extensive polling of the container height in embed module
app module minor cleanup
expose pep namespace to window

Exporting from app module did not work as expected.
Now you can start the first player on the page with
````javascript
    pwp.players[0].player.play();
````