I added a call to eth_estimateGas in case gas param is missing when using the upstream. This is a little bit ugly because I create an anonymous struct to match eth_call params. I spotted this struct in go-ethereum but I don't see it's exported.
This PR refactors RPC subsystem for status-go:
cleans up two different RPC client implementations (RPCManager and rpc.Client)
creates new package under geth/rpc
moves routing logic into this package (rpc.(*router))
add tests for routing
cleans up NodeManager
Geth requests have been revised and if the upstream is enabled, only queries regarding working Ethereum protocol are routed to upstream.
Whisper, most web3 requests and various utility methods are still routed to the local node as well as requests for accounts.
Now all transactions in both cases are waiting for CompleteTransaction or DiscardTransaction to proceed independently from their destination: upstream of local