Add noproxy configuration

When using request with noproxy, check if the url requested must use a proxy (if present) or not.
This allows requests on lan without having to change/disable the proxy parameter each time.

"noproxy" is a string containing hostnames. When using request with an url matching one of these hostnames, the specifed proxy won't be used.

So, this add a way to specify a list of hostnames that will not ever go through a proxy.