This function removes an object from the specified parent. Collections
will be removed recursively. You can pass an optional object query to
remove only those objects which match the query. An object will be
deleted physically if it is the last instance. The parameter array
contains the required elements 'objectidentifier' and 'parentidentifier'.
If you want to remove a user or group 'parentidentifier' can be skiped.
The optional parameter 'mode' determines how the deletion is performed.
In normal mode the object will not be removed physically until all
instances are removed. In physical mode all instances of the object will
be deleted imediately. In removelinks mode all references
to and from the objects will be deleted as well. In nonrecursive the
deletion is not performed recursive. Removing a collection which is not
empty will cause an error.
