allow the setup of default transcoding options on a per user basis

[nricciar]

These changes allow for setting the default transcoding options on a per user basis in the Access Control tab. This allows for automatic transcoding to any client regardless of their transcoding support.

Currently it exposes resolution, acodec, vcodec, and scodec along with a checkbox to enable or disable transcoding for each user account.

[nilzen]

:+1: for this!

[ghost]

Good option :)