Expose raw request path/URL in HTTP context

[cesarblum]

After normalization (see #573) we lose the raw request path/URL received from the client. Some applications might be interested in it, so we should expose the pre-normalized path/URL to them.

[Tratcher]

This will likely be exposed via a standard feature interface.

[DamianEdwards]

post RC2

[cesarblum]

Done #880