JWT support

[kavuri]

I am trying to implement jwt support in sails-oauth2-api and trying to implement the seamless user registration (if the user does not exist in the local db) I have added a check in isTrustedClient.js to verify if the grant_type is 'urn:ietf:params:oauth:grant-type:jwt-bearer'. From here onwards, I wanted to use https://github.com/xtuple/oauth2orize-jwt-bearer along with https://github.com/xtuple/passport-oauth2-jwt-bearer

Can you provide some pointers on the structure of the code and where I can go about implementing this? Once I am done, I can create a PR