Authenticate or create users from OAuth providers

Add 'notes' to path blacklist, fixes #4967

Update installation docs to use v1.7.1 of gitlab-shell

Rewrote init script.

Create satellites during update to 6.0. Fix #4938

add missing comma(s) in api examples

have email views use iid

Satellites for projects that were located in the root namespace needs to be recreated once they've been migrated to the creator’s namespace during the upgrade process.

This can be achieved by running the sudo -u git -H bundle exec rake gitlab:satellites:create RAILS_ENV=production during the update process.

The command has been added to the 5.4 to 6.0 update doc.

Dont update namespace if User name was changed. Use user#username for namespace name because Namespace#name validates by uniq

Standardize recently added commit diff api url

Fixed up wording on the new SSH key page.