polish documentation based on scrutinizer patches
remove duplicate param lines for OCP\User::getUsers()
Fix more documentation failes

Issue #7111
Merge branch 'master' into scrutinizer_documentation_patches

Conflicts:
	lib/private/appconfig.php
Merge branch 'master' into scrutinizer_documentation_patches

Conflicts:
	lib/private/migration/content.php
Merge pull request #7114 from owncloud/scrutinizer_documentation_patches

polish documentation based on scrutinizer patches