Account and Miner rpc and command enhancements
· Enhanced account command support for receipt identifier.
·Improved multi-sign command .
·Read-only account support.
·Support remove account command, no more restarting the node after the default account switch, and the lock/unlock rpc returns AccountInfo.
·Unify commands for Module upgrades .
·Added documentation for the stratum protocol and fixed a bug that caused lose hash rates.
·Improved Miner rpc return values.
·Improved block indexing tool .