This reverts commit 3e991230.

# Conflicts:
#	app/models/project.rb

- Makes the MR easier to read; this can go in a separate MR
- This is a (sort of) revert of 99bea01

The user has the rights of a public user execpt it can never create a project,
 group, or team. Also it cant view internal projects.

Added fields are last_sign_in_at and confirmed_at.
They are available for GET /users/ and GET /users/:id for admins.

Closes #840

Needed to support Huboard

- Offloads uploading to GitLab Workhorse
- Use /authorize request for fast uploading
- Added backup recipes for artifacts
- Support download acceleration using X-Sendfile

Added ability to update or set the identity of an existing user, like the documentation said it was possible, but actually wasn't.

Closes #2267

Closes https://github.com/gitlabhq/gitlabhq/issues/9391

Signed-off-by: NDmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

This reverts commit c0116926.

The requests were missing multiple required attributes, while testing for single attribute missing.
Added test for checking username as required attribute.

Signed-off-by: NJeroen van Baarsen <jeroenvanbaarsen@gmail.com>

Resolves #1916.

* users (#6878, #3526, #4209): Validation error messages are now exposed through 400 responses, 409 response are sent in case of duplicate email or username
* MRs (#5335): 409 responses are sent in case of duplicate merge request (source/target branches), 422 responses are sent when submiting MR fo/from unrelated forks
* issues
* labels
* projects

Signed-off-by: NDmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

Signed-off-by: NDmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>