lastkey calulation on primary index reopening

Issue 580: NPE on store reopen

Close connection in test

I was using the putIfAbsent API wrong

just seen a ConcurrentModificationException on Jenkins.

It looks like we can access the Map<Integer, Chunk> from different threads concurrently without taking the same locks. So make it a ConcurrentHashMap. Nothing useful we can lock on here without introducing an ABBA deadlock.

which is just the weirdest thing ever, and caused me no end of trouble trying to track down why my debugging statements where not appearing

preparatory work to splitting up the big test script

Fix for issue #600

now that we require Java1.7

Support more types in getObject