Added support for firefox getUserMedia

Added custom firefox streaming APIs.
Added minified version with support for firefox

Forgot minified version of headtrackr.js in last commit
Grunt build, AMD and commonjs support

Merged pull request from ryanramage with added grunt build, package
description and AMD and commonjs support.
Small fixes

-added license to grunt build script
-fixes to global export in header
-rebuilt headtrackr.js and minified version
readme.md formatting fix
Changed placement of messaging ui
Catch if canvasContext is not available yet

-small fix to catch if canvasContext is not available yet
(kudos to jkolivas for debugging and suggesting fix)
-also added revision-number to headtrackr object
Moved grunt.js, added example

-Moved grunt.js into src-folder
-Added link to real-time responsive typography
modified package.json

small modification to package.json
Add Snake to Projects that have used headtrackr

I also add some explaination to my demo ;)
Fix typo in realisticRelativeCameraControl
Merge commit 'refs/pull/14/head' of https://github.com/auduno/headtrackr into dev

Conflicts:
	README.md
Merge commit 'refs/pull/15/head' of https://github.com/auduno/headtrackr into dev

Conflicts:
	README.md
Rebuilt minified headtrackr.js

Rebuilt headtrackr.js & headtrackr.min.js with fixed typo from
tylermauthe