set share diff target based on address hash rate
log address not pubkey
was out of sync on a prior change
local_addr_rates may not have been in scope, fetch them instead
Storing results to use later instead of calling the function twice.
Extra APi stats, imported from p2pool-n
Merge branch 'master' of https://github.com/forrestv/p2pool into vardiffbyaddress
Logging change not required for new feature, conflicts the auto-worker-diff pull request
Merge branch 'minerstats' of https://github.com/roy7/p2pool