* Bump to 0.12.3.3
* Fix crash bug with duplicate inputs within a transaction
Introduced by #9049
* Remove redundant parameter fCheckDuplicateInputs from CheckTransaction
* Release notes 0.12.3.3
* Bump nPowKGWHeight for testnet and cause a fork at height 4001
This will reset testnet so that we can start with a clean state.
* Change CSV, DIP0001 and BIP147 deployments to start today
* Update nMinimumChainWork and defaultAssumeValid for block 4000
* Remove checkpoints above block 4000
* Bump to 0.12.3.4
* Update release-notes.md and copy 0.12.3.3 release-notes
* Don't check for nSuperblockStartHash on testnet
* Remove temporary fork handling for emergency difficulty reduction on testnet
As we reset testnet, we can also remove the special handling for old blocks.
