.. and print out the information. This sets up all the pathname
information, and whether it's a new file, deleted file, rename,
copy or whatever.
It's slowly getting to the point where it all comes together,
and we can actually apply all the information that we've gathered.
In particular, give line numbers when detecting corrupt patches.
This makes the tool a lot more friendly (indeed, much more so
than regular "patch", I think).
This applies git patches (and old-style unified diffs)
in the index, rather than doing it in the working directory.
That allows for a lot more flexibility, and means that if a
patch fails, we aren't going to mess up the working directory.
NOTE! This is just the first cut at it, and right now it only
parses the incoming patch, it doesn't actually apply it yet.
