refactor global variables

They are now all in app.js
add gameObject 'abstract' class
call initialize on object creation
add more constants
add Actor class
redefine global directions
compatible with my code

I had to edit a few lines for it to play nice with some of my (hawkish)
code
plain old XMLHttpRequest

getting rid of unnecessary bloat
edit GameObject.js
add playerActor subclass of Actor
add in new files
new assets