Add a CLI command that deletes an LDAP config

With this change LDAP configurations can be managed completely from
the command line.
cleanup group admin(s) on deleteGroup
Fix timestamp comparator return value
dont fail with 500 if configured display name attribute is not set
Close session for files_trashbin

When restoring huge folders the interface will be unresponsive otherwise
delete all children's previews when deleting a folder

add phpdoc
Clear session before setup

Fixes https://github.com/owncloud/core/issues/11861
Added script to build the JS documentation
Improved Javascript docs for JSDoc

Added namespaces so that JSDoc can find them.
Fixed a few warnings.
Improved some comments.
Dont' use mountpoint permissions as share permissions for external storages
Keep the share permissions from mountpoints
Add unit tests
user_ldap: Reimplement convertSID2Str() without BCMath dependency.

Also explicitly format sub-id integers as unsigned, which is required for
32-bit systems.
Update Symfony/Console to 2.5 & Update Symfony/Routing to 2.5
Fix ctor call in OC\Core\Command\Upgrade
Merge pull request #11172 from owncloud/user-ldap-no-bcmath

Fix ldap convertSID2Str() / Remove BCMath dependency
Capitalize Checks in admin page
Merge pull request #11923 from owncloud/admin-connectivitycheckscapitalized

Capitalize Checks in admin page
First check whether it is the default config before touchign

Potentially fixes https://github.com/owncloud/core/issues/11678
Merge pull request #11921 from owncloud/symfony-composer

Symfony composer