Added minor group functionality.

We added the ability to provide a group profile to the Stasis
command, which will in turn fetch the profile from the database.
A user will default to a participant if nothing is specified,
which enters the application like normal. Leaders and followers
are kept up with in groupsetup.js. Followers are put into the
waiting state (waiting for leaders). Leaders have no functionality
as of right now.

* Added database retrieval for groups
* Added a module to keep track of groups
* Added minor follower functionality
Finished basic group functionality.

Added leader and follower functionality. When a follower joins the
conference, they will be placed into a waiting state until a leader
joins, unless there is a leader already present. Leaders enter the
conference like normal and serve primarily as a trigger for
followers. Groups are configured in the database, just like users.
We also cleaned up some code here and there.

* Added leaders/followers/participants
* Did some minor code clean up
Addressed groups code review.

This is just a clean up commit before merging. Added helper
methods and made things look nicer.

* Cleaned up code
* Added helper methods
* Removed some unnecessary code
Merge pull request #13 from bkford/groups

Added minor group functionality.