through proxies.
Add a function to examine X-Forward-For and X-Real-Ip headers for
originating IP addresses. Use RemoteAddr for notification request
record and HTTP request context.
The new context package supports context-aware logging, integrating with
logrus. Several utilities are provided to associate http requests with a
context, ensuring that one can trace log messages all the way through a
context-aware call stack.
A full description of this functionality is available in doc.go.
Signed-off-by: Stephen J Day <stephen.day@docker.com>