MUC Service Plugin 0.2.0

- Extended the service with /participants endpoint to get all room
participants
- Extended the muc service to manage chat room roles (owners, admins,
members, outcasts)
Merge pull request #53 from Redor/master

MUC Service Plugin 0.2.0
OF-831: A typo on Database Settings page during setup, fixed the typo
Merge pull request #54 from Redor/master

OF-831: A typo on Database Settings page during setup