Merge pull request #33 from NightlyBuilds/NightlyBuilds-NBDiff

JS to take two .ipynb and generate the third file with diff info.
Add jshint to default grunt run
Moved all javascript code from html to a js file
Changed the diff.js to Diff.js
Changed the diff.js to Diff.js in the html file
Add node_packages to .gitignore
renaming the files to lowercase
Rename diff.{html, js} and fix build errors.
Fix merge conflict
Fix JSHint errors
Tabs -> spaces
Add eventlisteners after page has loaded.
Merge pull request #35 from tarmstrong/grunt-jshint

Add jshint to default grunt run
Adding test cases for diffing based on `git diff` as the reference implementation.
Add example test for compliance with reference diff implementation.
Break <div>s onto newlines
Remove existing cells
Fix css. Add style for row divs.
Rearrange cells so they are in divs for easier experimentation
Adding script for taking the first version of the prototype and making it easier to deal with.