feat(rpc): support the If-None-Match request header
If the If-None-Match header is supplied with a previously obtained ETag from the same query, a 304 Not Modified is returned with no content.
This allows clients to completely leverage the ETag header.
Signed-off-by: Kevin Morris kevr@0cost.org
P.S. snuck in a fix for JSONP callback.
Edited by Kevin Morris