Check for unique player name
Check for unique ship name

* changed how addPlayer passes error message to caller
Merge branch 'master' of https://github.com/feibeck/StarshipMayflower

Conflicts:
	game-server/app/servers/world/handler/lobby.js
	game-server/app/src/world/ShipRegistry.js
	web-server/public/src/StarshipMayflowerLobbyControllers/controller/StarshipMayflowerLobbyControllers.js
Fixed function name that changed after merge
Merge pull request #12 from brichter89/master

Improved checks for unique / valid player / ship names