Flatten the tmpl_if tree for determining the item status
to display and tweaked the order in which statuses are checked to
1. (circ reality) item on loan
2. (circ reality) item in transit
3. (circ reality) item wating at hold shelf
4. (item status that makes circ impossible) item withdrawn
5. (item status that makes circ impossible) item lost
6. (policy that implies no circ but in-house use possible) item not-for-loan per item
7. (policy that implies no circ but in-house use possible) item not-for-loan per item type
8 (item status that *might* affect circ) damaged
8. (fallback) item available