Entity fixes

* Initialize options as an empty object if nothing is passed
* Correctly access input key values
* Fix down / up y axis math. derp.
Add call to #beginPath before drawing entity
Add a second client to check if everybody is synchronized
Render all clients of world state

* Add keyboardState as default empty object
* Properly enqueue data from "network" on 'world-update' event
* Create new entities for each new client returned on worldState
* Render other clients
* Fix deltaModifier by making a proper second fraction (Date.now() returns timestamp in ms)
Properly fake 100ms lag - Prediction + reconciliation i need uuuu :OOO
Add #render method to Server to it's easy to see what is going on

* Properly bind 'this' value on #newClientConnection
* Render server on update
* Update server to receive a context to draw on
Simulate world with two clients
Browserify it all to actually see stuff in index.html, it's kind of alive now :)