cron shall not operate in case we are in maintenance mode

Add cURL as hard-dependency

It is required by other functionalities such as S2S anyways and ownCloud will fail hard at a lot of places without it.

we no longer support webdav locks - no need to keep the column

Do not overwrite the active menu entry of the navigation

Install command should not require table prefix

Fix the avatarcontroller cache needing the cache dir

Run `updateDataDirectory` after Update

This was removed in 82254ad5 and
unfortunatly missed by jenkins before mering into master.

Move AvatarController to AppFramework

Only make sure the cache directory exists when we use it

* 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

Setting oci as supported database

Add a console command user:add to create users over the console

Add support for font previews

Allow iframes from same domain in share view

Merge pull request #13839 from owncloud/issue/13678-improve-remote-domain-detection-in-sharedropdown

Better finding the remote URL from user input in share dropdown

Do not abort when meeting unfixable legacy storages

Adding a more meaningful message for sabre dav exception

Correct "one invalid characters" to "one invalid character"

Add an option to include the installed app version in "occ app:list"

display app update error messages

Use occ to install ownCloud in autotest.sh

Corrected "one invalid characters" to "one invalid character" in line 1575.