Move the server code in its own subdirectory
Split server.js into modules

server/
├── logger.js
├── presence.js
└── server.js
Move server tests into a test/server/ prefix
Server: create a thin abstraction object for users
Server: use the new Users abstraction
Server: create a class for individual users
Server: document User and Users classes
Fix minor typos
Merge branch 'master' into refacto-server-users

Conflicts:
	Makefile
Merge pull request #181 from tOkeshu/refacto-server-users

Refacto server users