Allow custom arguments to be passed for reply comment requests.
Review Request #6418 — Created Oct. 8, 2014 and submitted
This updates the reply comment resources to allow for unknown arguments
without triggering validation errors. We need this in order to use
fields like force_text_type (for now) and extra_data.This matches the behavior of other comment resources.
Tested each of these resources one-by-one and was able to pass whatever I
wanted without validation failing.
