Bower registration (incomplete)

This adds a bower.json to the project so we can publish editableCell on [Bower](http://bower.io)

However, we need at least the following covered first:
* #19 - we should include the license type in the bower.json  
* #20 - I've searched in Bower and found 44 packages using 'knockout-{package}', 24 using {knockout.{package}', 10 using 'ko-{package}', and 3 using 'ko.{package}', so I've chosen 'knockout-editableCell'  
* authors: I've put in your github user names, but the spec defines multiple ways. Just comment which you prefer.

@gnab @espenh