tpcc: assertion is too aggressive
allocator: add memcheck option
rcu/allocator: lots of sanity checking memory instrumentation

still can't find that damn bug
rcu: add a stress tester
rcu/btree: more stress testing
rcu: fix off by one bug that was causing premature deletions

grrr... so much fail...
usused debugging comment
tuple: add a debug mode to check if writing valid memory
allocator: change some aggressive asserts to invariants
test: restore test cases to be useful for general development