Native Consensus to Meta Consensus connectively

[fuxingloh]

Consensus issues that are directly related to Native Chain and Meta Chain connectively. Asset bridging is built on-top of the base connectively hence moved out of this picture.

Issues

• Finalize Native Threading Model as it affects DMCHandler() #94
• Payload Embedding & Propagation on Native P2P #93
• meta-consensus-rpc module for consensus #89
• JSON-RPC communication between Native Chain and Meta Chain #80
• Secured connectivity between Meta Chain and Native Chain #45
• FFI communication between native and meta chain #106