Route methods via diffrent protocols

[splix]

Some methods like eth_getLogs produce very large response, tens of megabytes. Tracing and debugging methods even larger, could be 1Gb+.

But when WebSocket is used with Geth it tries to send the response in one large frame. That's ineffective.

Instead of using WebSocket protocol for such requests, Dshackle should make standard HTTP request if it's available. Make it configurable, with default config for eth_getLogs, trace_replayBlockTransactions, trace_replayTransaction, and debug_traceTransaction

[splix]

see #138