Full chain testing

The experiments want to test out the complete data management chain, from experiment pit->Tier-0->Tier-1->Tier-2. This exercise has been given the snappy title of Common Computing Readiness Challenge (CCRC) and is expected to run in a couple of phases in 2008: February, then May. This will be quite a big deal for everyone, and we need to make sure the storage is ready to cope with the demands. SRM2.2 is coming "real soon now" and should be fully deployed by the time of these tests (well it *had* better be...), which will make it the first large scale test of the new interface.