Extract authentication actions from `UserController`

Because it has not been tested yet.

To make it slightly more readable

It did not make sense to manage login/logout actions from
`UserControllers`, reason why they were moved to its own controller.

Note that this change also implies modifications in routes

  - GET  user_login_path    -> GET    session_new_path
  - POST user_do_login_path -> POST   session_create_path
  - POST user_logout_path   -> DELETE session_destroy_path

We now always allow stripping of the first component if the
first entry is a directory.

That way people learn how to access their containers.

Adding an optional pushserver config, for registries having an own push interface

[frontend] Temporarely skip test

This test currently blocks our package builds because it's constantly
failing there (We run all our tests within the rpm package builds again).

[frontend] Refactor request validation test

[frontend] Sanitize patchinfo input before saving it

Reduce cassette size

If the request creator is not confirmed, he might get might not get
logged in. Therefor it's better to user some other request related
validation.

[frontend] Fix fuzzy time, part II

Remove leading / trailing whitespaces from rating and category.

Fixes #4662

Refactor js for patchinfos

[frontend] Fix expert mode for adding repositories

Re-apply changes made in 8f8c5ffe

This broke with a439c3e6

Fixes #4740

[frontend] Auto-correct rspec offenses after updating rubocop-rspec

Fix ProjectLogEntryUserName migration

* Add an event handler to track changes of the add issue link
* Skip before action callbacks we don't need
* Remove hidden field values that are now tracked via data attributes

This broke with 0a90a752

Fixes #4764

Makes debugging interconnect issues a bit easier.

Update momentjs-rails: 2.17.1 → 2.20.1 (minor)

The migration did not work. Let's test this so it won't happen again.

[frontend] Update exception handling in event mailer

Update rubocop-rspec: 1.20.1 → 1.24.0 (minor)

[webui] Prevent Logout from redirecting to the homepage.

[frontend] Prevent codecov reports being send outside of travis

[frontend] Fix flickering test

Fix nplus1 query

We only need this for travis to have codecov reports for every pull
request and the master branch.
On our development instances sending the report always fails due to a
timeout (~30sec).

Freeze time to avoid race condition.

Fixes #4619

Re-raise exception instead of raising a new one. This ensures that we
don't loose data related to the exception.

This previously changed with 1f259e35