* Original avatarcontroller migrated to the appframework
* Added DataDisplayResponse that show data inline in the browser (used
to retrun the image)
* Removed some unneeded code
* Added unit tests for the avatarcontroller
This patch wil warn the user of the consequences when resetting the password and requires checking a checkbox (as we had in the past) to reset a password.
Furthermore I updated the code to use our new classes and added some unit tests for it 👯
Fixes https://github.com/owncloud/core/issues/11438
