0) Adjust BIP30 enforcement values
1) Reduce amount that peers can adjust our time to eliminate an attack vector. Thanks to
coblee for this fix.
2) Zeitgeist2 patch - thanks to Lolcust and ArtForz. This fixes an issue where a
51% attack can change difficulty at will. Go back the full period unless it's the
first retarget after genesis.
3) Avoid overflow in CalculateNextWorkRequired(). Thanks to pooler for the overflow fix.
4) Zeitgeist2 bool fshift bnNew.bits(). Thanks to romanornr for this path.
5) SegWit ContextualCheckBlockHeader adjustment and extra coverage.
6) Reject peer proto version below 70002. Thanks to wtogami for this patch.
7) Send final alert message to nodes warning about removal of the alert system. Thanks to coblee for this patch.
8) Adjust default settings for Litecoin.
9) Adjust STALE_CHECK_INTERVAL value
Most bitcoin.conf options apply to all three networks,
however some apply only to mainnet unless specified in a section.
As stands, conf file has no indication that sections are now in use
or are in some circumstances mandatory (eg, changing rpcport for testnet.)
Proposed change notifies the reader early which options are affected,
specifically adds those options affected but not already in the example,
adds brief explanation as to what's going on and provides a skeleton template for the sections themselves.