Use grunt to build scripts.  Fixes 141

changing the version in package.json will now update bower, the header
comments, version.js, the src file names, and all the places those src
files are used.  The banner is now automatically included at the tops
of script files. yay.  Still need to go through and clean out the
makefile, but that can be done later.
Add grunt watch
Fix browserify ignore
Add load-grunt-tasks
Downgrade uglify to support node 0.8.0
Add Grunt task for running tests
Downgrade load-grunt-tasks for node 0.8 support
Merge pull request #161 from leapmotion/grunt

Use grunt to build scripts.  Fixes 141