v2.2.0.6

UI: Fix a UI freeze that was occuring on 'finished' witness accounts
RPC: Fix a crash in 'signrawtransaction' when signing new transaction types (of non script type)
RPC: Improve 'dumpblockgaps' command to output data for both witness and PoW timestamps; previous behaviour considered PoW timestamps only
RPC: Backport/add 'uptime' command from upstream
RPC: Backport/add 'getblockstats' command from upstream
RPC: Update second paramater of 'estimatesmartfee' from bool to string to match changes in upstream
RPC: Add output of witness/spending pubkeyhash when calling validateaddress on a witness address
CORE: Fix an issue some wallets were having with signing extend/optimise transactions
CORE: Remove various parts of the old phase3 codebase, this should bring performance improvements