Version Updates. Resolved compatability problems

* Remove knockout.meteor.coffee
* knockout.js 2.2.0 -> 2.2.1
* knockout.meteor.js 0.2.4 -> 0.3

Other versions of knockout.js have been tested (v2.3.0, v3.0beta), only v2.2.1 works fine with Meteor@0.6.4.1