Awesome crate, let's make it even better

[remimimimimi]

Hi, thank you for such an awesome crate! I've been working on my own fork of diffy with a lot of additions required to replace git in patch application during package build for rattler-build and was thinking about integrating some of them back.

There are several things that I did:

1. Dirty hacks to fix parsing for different patch files.
2. Parsing of multiple patches (in your terminology) in one file.
3. @wolfv added support for fuzzy matching.
4. Tests of some patches from conda-forge.
5. Hunk parsing strategies.

There are some more things incoming, but list above is what we have right now. Which one you would like me to integrate back?