* Drop registry deletion of the old key
* Drop no longer used CGovernanceObjectVoteFile::RemoveOldVotes()
* Drop temporary disconnect code and bump min protos to 70213
* drop comment
* fix
* Clear votes which were created before spork15 activation
* Reject incoming votes which were created pre-DIP3
* Only use voting keys for VOTE_SIGNAL_FUNDING
The other vote signals are meant to be emitted by sentinel and must thus
be signed with the operator key.
* Simplify GetMinVoteTime
* Review suggestions/fixes
* Add missing mutex in CGovernanceObject::RemoveOldVotes
* Store masternodes in a map instead of a vector, drop unused functions in CMasternodeMan
* CTxIn vin -> COutPoint outpoint
* do not use CMasternodeMan::Find outside of the class
* update GetMasternodeInfo
* safe version of GetNextMasternodeInQueueForPayment
* fix ProcessMasternodeConnections
* bump CMasternodeMan::SERIALIZATION_VERSION_STRING