Support for replacing a response by a new one

[mathieucarbou]

This really simple PR allows for a very nice feat: ability to override a previously prepared response, in order tp build a new one.

the real sending will happen once the handle exist, not in the send method anymore.

this will allow to have middleware support for response headers too!

[mathieucarbou]

@DRSDavidSoft: FYI

[DRSDavidSoft]

@mathieucarbou Wow, this is some excellent addition! How does it work internally? Also, what was the previous behavior, for reference?

Thanks for adding this too! 👍🏻

[mathieucarbou]

@mathieucarbou Wow, this is some excellent addition! How does it work internally? Also, what was the previous behavior, for reference?

Look at the code ;-)