New Options, improved stability

--quantum         opts-in to quantum data vs. being the default.  Will fallback to crypto/rand on failure
--walletfile      loads wallet list from wallets.json in working directory and rotates through 1 wallet per job

Changed to 4byte mining space, need to leverage 4 byte miner for optimal results.
Increase quantum cache, and optimize quantum fill frequency by triggering fill and then waiting until it drops below original threshold to re-trigger fill to new max.