Fixed a problem with detaching attachments in situations where the user's asset server is not the same as the simulator's asset server. Unfortunately this still continues to be wasteful -- new assets are created every time an attachment is detached, but the process of storing the new asset goes through the InventoryAccess module, which does all sorts of checks regarding the users' inventory.
Merge branch 'master' of ssh://opensimulator.org/var/git/opensim