Logging support

[pyhedgehog]

It would be very pythonic to use jq_set_debug_cb() and jq_set_stderr_cb() and set callback that will pass it's input to stdlib logging module (by Vinay Sajip).
I propose i.e. logging_path parameter to use as argument of getLogger, and by default either "jq" or disable feature (if it will be too resource-heavy).