Generate BigbluebuttonRoom#room_options in the migrations

Also updated bigbluebutton_rails and removed the default layout to be
empty and not 'Default'. Empty means that the default layout from
BigBlueButton/Mconf-Live will be used.

refs #960
Fix db:populate, was failing generating Space#permalink

Wasn't generating the permalink properly and was failing when saving spaces.
Made also some other smaller improvements.
Re-enable and improve select2 visually

It was mistakenly disabled by 71768bc35e
Also made it look better, especially in the view invites/invite_room
that was looking pretty bad after it was changed to use select2.
Merge branch 'branch-v1' into mconf.com-demo