Multiroom support

[iamDecode]

Basic implementation of multi-room support as proposed in #8. This change just duplicates the services for each room. Some things still left unexplored:

• The rooms menu is currently populated statically from the rooms config file. It would be nice if more dynamic information like number of users currently in that room could be shown as well.
• Switching rooms is currently done by refreshing the page. Thats a bit excessive, properly unloading App and loading a new one for the new room is probably better.
• broadcast/subscribe is currently done with a bit of a hack, prefixing every namespace with the room name. Should check out if uwebsockets has some sort of scoping system for broadcasts.

Closes #8