Users should not be given the impression that they can modify these items.
This still does not solve the issue where library items cannot be dragged into prims or user inventory any time after they are initially seen.
Curiously, manually copying and pasting still appears to work.
On the surface, this seems to have something to do with library item caching on the client, since deleting the cache allows drag to work again once
Not sure what the exact problem is.
Some items had completely wrong permissions - this is easier than correcting them all.
The ability to set permissions in xml is retained since there are use cases for this (e.g. to create no-mod library scripts)
Library items always need the same permissions, so it doesn't make sense to load them from the xml files. This just opens the door to permissions mistakes.
When this switch is used, iar folders are merged with existing same-name user inventory folders.
This makes it a little easier to back and restore entire individual user inventories, among other things
Added unit test to check behaviour
