Adding some notes about TDD
[devtools] Markdown sublime junk for Ben
Makes install.rb in markdown/ executable
Makes install.rb in markdown/ actually work
[wip] Factors pixi stuff in game.js into graphics.js

Also adds some handy utility methods to utils.js, wrapped in an object
that I'm calling 'js' for now (as in 'javascript').

The game is now initialized and started in index.html, instead of cave generator demo.
Made it easier to switch back to the cave demo.
[graphics] Renamed private pixi api
Converts tabs to spaces in index.html
Moves declaration of '_ticker' private member of game
Deletes extra 'utils.js' (it was added by mistake)
Checks for system name before adding a system.
More work on systems
Fixing bugs in entity and system
Merge branch 'master' of github.com:flyingrobots/caverns into dev/systems

Conflicts:
	client/src/engine/utils.js
Got systems working
Fixing bugs with systems
Systems are now working
Removed test html