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
Fixes bug in FirebaseArray's setting of $priority during remote updates
Fixes priority.spec.js e2e, removes sleep
Merge pull request #360 from firebase/release_script

Added release.sh script and other repo cleanup
Minor updates to priority e2e test
Fix failing unit tests ($priority related)
Merge branch 'release_0.8_prifix' of github.com:firebase/angularFire into release_0.8_prifix
Merged with release_0.8 branch
Merge pull request #361 from firebase/release_0.8_prifix

Fixes bug in FirebaseArray's setting of $priority during remote updates
Fixed improper use of npm test
Merged with release_0.8 branch