Preserve attachment point & position when attachment is rezzed in world

Patch taken from
http://opensimulator.org/mantis/view.php?id=4905
originally by Greg C.

Fixed to apply to r/23314 commit
ba9daf849e7c8db48e7c03e7cdedb77776b2052f
Don't use 'Indented' formatting for RpcXml responses.