[FEATURE REQUEST] Add line offset correction when patching with context diffs

[PGgamer2]

As stated in the patch manual:

   With context diffs, and to a lesser extent with normal diffs,
   patch can detect when the line numbers mentioned in the patch are
   incorrect, and attempts to find the correct place to apply each
   hunk of the patch.  As a first guess, it takes the line number
   mentioned for the hunk, plus or minus any offset used in applying
   the previous hunk.  If that is not the correct place, patch scans
   both forwards and backwards for a set of lines matching the
   context given in the hunk.  First patch looks for a place where
   all lines of the context match.  If no such place is found, and
   it's a context diff, and the maximum fuzz factor is set to 1 or
   more, then another scan takes place ignoring the first and last
   line of context.  If that fails, and the maximum fuzz factor is
   set to 2 or more, the first two and last two lines of context are
   ignored, and another scan is made.  (The default maximum fuzz
   factor is 2.)

This feature would greatly improve the package

[aberteau]

Hi @PGgamer2,

Thank you for this issue.
I have to admit that it's been a long time since I got my hands on this library. 😅
I'll have to dive back into it. I'll see what I can do.

In the meantime, if you have an idea of ​​what changes should be made, feel free to submit a pull request. 😉

Regards,
Amael