CONSENSUS:
Implement proposed reward reductions and halving, as decided by community and GAB
Reward changes to take place at block 1'400'000
Halvings every 842'500 blocks, this is roughly four years assuming stable block times (a tiny fraction over in order to make things work out smoothly)
Very minor truncation based rounding applied when halving in order to keep numbers clean and end on a clean supply amount
Final supply of 700'000'000 with last reward mined on block 17'727'500
CORE: Implement a new/simplified way of tracking the witness specific portion of the UTXO set, this improves code simplicity as well as efficiency in a variety of ways
CORE: Implement methods/functionality to track/encode witness set "deltas" (changes) between blocks
CONSENSUS: Store the witness set delta as part of each header, this allows for a very efficient syncing method which we are calling "witness sync"
CONSENSUS: Enable spending of addresses with uncompressed keys again
CONSENSUS: Allow renewal of multiple parts of the same witness account in a single transaction instead of requiring a renewal for each part
CORE/UI: Introduce a separate mining parameter for number of threads to use for "arena setup" when mining so that this can be set independently of "mining threads"
CORE: Fix a sync issue that would sometimes cause new installs to get stuck when syncing the first few blocks
CORE: Apply some optimisations to ConnectBlock calls that should improve performance quite substantially on some machines
RPC: "setgenerate" gains an extra parameter for the above, all miners should be aware of this as previous setgenerate syntax may fail
RPC: New command "setwitnessrewardaddress"
RPC: New command "restoreaccount"
RPC: Improve behaviour of "deleteaccount" to permanently remove/purge accounts from the wallet if they are readonly accounts; as opposed to the regular behaviour of just hiding accounts that applies to other account types
RPC: Fix return value of "enablenetwork" command
RPC: Add "selected_shavite_implementation", "selected_echo_implementation" and "selected_argon_implementation" to "getmininginfo" output
UI: Show "elapsed" time to current date for witness accounts
ZMQ: Add a new ZMQ channel "zmqpubwallettx"
And a variety of other small performance, stability and code quality enhancements, general maintenance etc. many of which are backported from the Florin project.