v2.3.0.0

CORE - Set checkpoint server deactivation for 1602774915 (Thursday, 15-Oct-20 15:15:15 UTC)
Checkpointing is now no longer required with witnessing now fully implemented and stable as per the original whitepaper specification
NET - Disallow all peers below protocol version 70018 after timestamp server deactivates
RPC - Correction to return value of 'enablenetwork' command