Enable API projects management

This enable an API for
/api/v1/projects.json
/api/v1/projects/:id/builds.json

This will allow to create projects from the command line as soon as user knows his access token. The tokens will be a new column on the users table and a rake task needs to ran to generate tokens for every existing user. New users will have it by default. The token will show up on the top of the screen.