Porosity integration (Consensys#155)

* Addition of quorum.runPorosity and quorum.getPrivatePayload

Add Raft-based consensus (Consensys#79)

This was implemented by Joel Burget (@joelburget) and Brian Schroeder (@bts).

Merge pull request Consensys#60 from obscuren/quorum-private-logs

core, eth: support private state log and bloom filtering

Revert "core/quorum: check if transaction was already applied" (Conse…

…nsys#33)

Update README.md

Merge pull request Consensys#17 from jpmorganchase/nonce

core/quorum: check if transaction was already applied