The 7.22 release is out. This is mostly pdfwrite stuff. We're trying to shoot for an 8.0 release by Seybold, 10 Sep. It's tight, but we might just be able to pull it off. One of the things we're trying this time is a "bug bounty". It'll be interesting to see how that works out.
Do hash potatoes grow in Galois fields?
David McCusker wonders how to choose a CRC polynomial for 64 bits. Leaving aside the question of why, here's a generic discussion of LFSR's, and an application note geared towards FPGA's, but still reasonable. Also see this note on why concatenating two 32-bit CRC's doesn't work.
But CRC's are pretty bad hashes. Collisions are very easy to generate, one of the usual criteria for hash quality. It's hard to imagine an application for which a 32 bit CRC is inadequate, but a 64 bit CRC is a good choice.