PHPDoc Improvements

Add tests for other types that PHP might cast

Addition to https://github.com/owncloud/core/pull/8572

Fixed:
- An error with a misplaced bracket in lib/private/util.php
- An error with an incorrect function being called in lib/public/contacts.php

Some things my IDE complained about while creating a custom backend.

Fix PHPDoc and typos

Some things my IDE complained about while creating a custom backend.

Conflicts:
	lib/private/group/database.php
	lib/private/group/dummy.php
	lib/private/group/example.php

Fixed getAbsolutePath case when path is "0"

Make sure to correctly check for string emptiness when the passed path
is "0".

Add prompt dialog to OC.dialogs

backup the encryption key after the encryption was disabled

Allow setting of controller default method values through normal PHP default values

can restore them if needed

Extract mount point merging logic into separate function

fix sticky footer on log in page

escape display name and email

Rotate thumbnail when encryption is enabled

Kill legacy code master

Use proper PHPDoc and variable names in the LDAP lib

adding X-Robots-Tag to all responses of ownCloud + move addSecurityHeade...

Make logger available in the container