Refactor rpc/tm to rpcinfo changing various names.

Add more useful information to /status /network and /consensus
Blockchain now records when it last committed a block as well as the
block time itself. Status can be used for a liveness probed with
block_seen_time_within param and block_time_within  for readiness

Signed-off-by: Silas Davis <silas@monax.io>