Updated Request/Response implementation

[wallyqs]

Port of the current implementation of request/response from the Go client, where a single subscription with a wildcard is responsible of handling the responses.
This style of request can be used via the request API, but without passing a callback parameter which now is changed to block and wait for a single response. This style of request/response is also faster than previous implementation:

# Before:

$ python3.6 benchmark/latency_perf.py 
Sending 10000 request/responses on [test]
#######################################
Test completed : 0.340 ms avg request/response latency

# After:

$ python3.6 benchmark/latency_perf.py 
Sending 10000 request/responses on [test]
#######################################
Test completed : 0.284 ms avg request/response latency