Update Canvas.js

Support Canvas Security Limit. http://www.w3.org/TR/cors/
Adds a maxDimension feature to ColorTracker. mergeRectangle returns rectangles that satisfy minDimension and maxDimension requirement
Sets default value for maxDimension
update tracking-min.js and tracking.js
Source formatting
Defaults found color rectangles max dimension to Infinity
Source formatting
Adds tests for color dimension constraints
Fixes docs
Build
Merge branch 'pr-94'