* Move code to write archived ISLOCKs into its own method
We'll need this from another method as well later.
* Return ISLOCK instead of conflicting txid in GetConflictingTx/GetConflictingLock
* Implement GetInstantSendLocksByParent and RemoveChainedInstantSendLocks
These allow to easily delete multiple chains (actually trees) of ISLOCKs
in one go.
* Implement RemoveConflictedTx and call it from RemoveMempoolConflictsForLock
Also add "retryChildren" parameter to RemoveNonLockedTx so that we can
skip retrying of non-locked children TXs.
* Properly handle/remove conflicted TXs (between mempool and new blocks)
* Track non-locked TXs by inputs
* Implement and call ResolveBlockConflicts
* Also call ResolveBlockConflicts from ConnectBlock
But only when a block is known to have a conflict and at the same time is
ChainLocked, which causes the ISLOCK to be pruned.
* Split out RemoveChainLockConflictingLock from ResolveBlockConflicts
* Implement "quorum getrecsig" RPC
* Include decoded TX data in result of create_raw_tx
* Implement support for CLSIG in mininode.py
* Fix condition for update of nonLockedTxs.pindexMined
* Only add entries to nonLockedTxsByInputs when AddNonLockedTx is called for the first time
* Implement support for ISLOCK in mininode.py
* Implement tests for ChainLock vs InstantSend lock conflict resolution
* Handle review comment
Bail out (continue) early
