Set up CORS hander for error responses

See https://github.com/strongloop/loopback/issues/575
Merge pull request #106 from strongloop/feature/fix-lb-575

Set up CORS hander for error responses
Bump version
Merge branch 'release/2.2.0' into production
Merge tag 'v2.2.0'

2.2.0
Merge branch 'release/2.2.1' into production
Merge tag 'v2.2.1'

2.2.1
Fix missing assert
Remove stupid assert global
Merge pull request #108 from strongloop/fix/assert-shared-method

Fix missing assert
2.2.2
Support prototype methods via HttpInvocation
Fix isAcceptable to process Model objects
Fix http-invocation test

* Fix call from http-invocation.test.js to account for constructor arguments
Add prototype shared method tests