Merge tag 'v1.6.0'

v1.6.0
Add debug information for user.login
Remove message prefix as debug will print it
Remove the generated flag for access token id

The generated flag is used to indicate if the id is automatically generated
by the backend store. If it's set, the data type will be updated when the
model is attached to a datasource.

The AccessToken model defines a string id, which is set in the beforeCreate
hook. So it's client provided id.
Merge pull request #164 from strongloop/feature/fix-accesstoken-id

Remove the generated flag for access token id
Describe `access_token` param of `User.logout`

Add an explicit note that clients are not supposed to send the
`access_token` parameter, since it is extracted from request
headers.
Add `include=user` param to `User.login`

Allow LB clients to get details of the currently logged-in user
as part of the login response.

Improve method's `description` to mention this new option.
Merge pull request #154 from strongloop/feature/debug-login-error

Add debug information for user.login
Merge pull request #163 from strongloop/feature/include-user-in-login-result

Include user in login result
v1.6.1
Merge branch 'release/1.6.1' into production