Added release.sh script and other repo cleanup

- Removed need to install grunt-cli on Travis
- Updated README
- Cleaned up package.json
- Cleaned up bower.json
- Created change log
- Changed header format for dist/angularfire.js
- Added release.sh script
Fixed TODO in bower.json
Preserved headed on minified diet file
npm travis not a valid command
Merge pull request #360 from firebase/release_script

Added release.sh script and other repo cleanup