Updated readme and ignore

Added thelink to the wiki in the readme
Fixed #1

Tab index is now always 0
Fixed #5
Documented Utils.uniqueArray
Fixed #12

Only getWidth() was concernedby this bug.
Fixed #8

Removed all references to filters. I'll create a separate branch to
reimplement them.
Removed filter property fromDisplayObject

Related to #8
Implemented #15

This totaly breaks backwards compatibility.
Fixed #16

Math package is now declared in cannon.js, and the Matrix object too.
Line and Shapes still require math package.
Fixed #2 and #4
Fixed #11

Vertex2D now stands alone and is simply composed of 3 Points2D
Fixed #3

Most vector methods are now chainable. Fixed some style issues as well.
Made Point2D chainable

As per #3