Adding bluebird for promises
Uses bluebird for promises

 - Throws an error when rejecting promise
 - Improves promise rejection (Returns Error instances instead of objects)
Uses nodeify to kill some code
Using Promise.promisify to use less code on Model.get
Promisify model._db
adding repo
Merge remote-tracking branch 'upstream/master' into bluebird

Conflicts:
	package.json
	test/test.js
Promisifying more and fixing a test
Always returns model on save
Merge pull request #1 from jeduan/bluebird

Bluebird