Move queueNearbyChunks into ChunkManager in order to simplify Client code.
Remove conn as a field on player, make error handling more consistent.
Merge remote-tracking branch 'origin/dev' into server-refactor

Conflicts:
	server/src/buildblast/server/client.go
	server/src/buildblast/server/main.go
Remove globalWorld.
Refactored connectiony parts of Client into ClientConn, making it so Client is only dealing with two concurrent threads, rather than 4.
Remove User, make Client responsible for Player instead (which is now a sane thing to do, since Client has become much less complex)
Make Game.clientWithID() not racy (fixes #87).
Stop using channels for entity events in World, switch to event-based system instead. Partial fix for #86.
Remove Client.Send(), use less hacky solution.
Remove map.go (not sure how it got there...)
I think #86 should be fixed now.
Moving knowledge of Msg* outside of Player (and into Client).
Move core game logic into seperate game/ package.
Don't print annoying error messages in conn.go, put debug timing statements around correct block of code.
Add Player quit messages, kill annoying log messages.
Remove extra space in quit message.
Don't print ANY silly errors in conn.go.
Fix clientRequests race condition.
Added helpful comments.
Merge pull request #89 from crazy2be/server-refactor

Server refactor