Remove external deps from codebase

[jsloyer]

Remove external deps from codebase. This resolves licensing issues with external deps. Use bower to install external deps to www/external. Update README to include how to build the app with bower

[pliablepixels]

the external directory consists of files I modified from the originals. Ideally, I should have forked and pulled, but I did not. So we can't pull in originals. They are all MIT licensed or AS IS licensed. I will write up a license disclaimer for all of them in a single file