Move Share20OCS to ShareAPIController

It was already a controller just still residing in its old location.

* Moved ShareAPIController to user plain userID instead of user object
* Moved Share20OCS to ShareAPIController
* Removed initisation of class from Application.php and leave it to the
AppFramework
* Fixed tests

Signed-off-by: Roeland Jago Douma <roeland@famdouma.nl>