In order to properly test the mimetype function:

* constructor takes path to configdir
* Added unit tests for mimetype (only if vfsStream is available)

* Copied unit tests from old functions

See https://github.com/doctrine/dbal/pull/782 for more info

When returning a 500 statuscode external applications may interpret this as an error instead of handling this more gracefully. This will now make return a 401 thus.

Fixes https://github.com/owncloud/core/issues/17742

remove unused import

add since tag

fix typo

Remove information about whether a file is an incoming share or mount
point when requested over public webdav.

Update sinon to 1.15.4.
Update karma-jasmine to 0.3.0
Update jasmine to 2.3.4

This brings a bunch of new useful functions for unit testing.