improved (transaction ...), now moves docstring and copies declarations from autogenerated lambda to actual function
performance improvement: new (valid-and-unlocked?) function called by (commit) that works without locking transactional reads
performance improvement: replaced read-write locks with faster compare-and-swap
improved (wait-tlog) invoked by (retry), now repeatedly sleeps until transaction log becomes invalid
updated docs
new multi-threaded benchmarks
fixed atomic-counter type declaration for 32-bit implementations