I've pushed two changes to https://github.com/jtoomim/p2pool/commits/1mb_segwit:

1. Allow mining with clients that do not support all locked-in or active forks (e.g. Bitcoin Core which does not support segwit2x) if p2pool is run with the --allow-obsolete-bitcoind command-line option.
2. Switch back to using time.time() in order to hopefully fix Xantus's "exceptions.OverflowError: mktime argument out of range" error on Windows