refactor studio and composer into modules

- fix unit tests
- change Profile to User module
- adjusted the request interceptors for Studio and Composer
-- studio does auth checking
-- Composer does error checking

- renamed User module to StudioUser module

- convert strudiouser name to studio-user

- convert console.warn to $log.warn
Merge pull request #409 from strongloop/feature/refactor-studio-composer

refactor studio and composer into modules