Move all Etherpad's access control from Meteor to a separated [Node application](https://github.com/bigbluebutton/bbb-pads).
This new app uses [Etherpad's API](https://etherpad.org/doc/v1.8.4/#index_overview)
to create groups and manage session tokens for users to access them. Each group
represents one distinct pad at the html5 client.
- Removed locked users' access to pads: replaced readOnly pad's access with a new pad's content sharing routine
- Pad's access is now controlled by [Etherpad's API](https://etherpad.org/doc/v1.8.4/#index_overview)
- Closed captions edited content now reflects at it's live feedback
- Improved closed caption's dictation mode live feedback
- Moved all Etherpad's API control from Meteor to a separated [app](https://github.com/bigbluebutton/bbb-pads)
- Included access control both in akka-apps and bbb-pads
When managing Etherpad's pads, Meteor makes API calls to initiate the closed captions
and shared notes modules. The pad id was being mapped to a shorter id than the meeting
id because of a Etherpad lenght limitation.
Changed to something less guessable.
