Major changes in version 2.3:

* New diff option: --horizon-lines=lines


Major changes in version 2.1:

* New diff options:
  --{old,new,unchanged}-line-format='format'
  --{old,new,unchanged,changed}-group-format='format'
  -U
* New diff3 option:
  -A --show-all
* diff3 -m now defaults to -A, not -E.
* diff3 now takes up to three -L or --label options, not just two.
  If just two options are given, they refer to the first two input files,
  not the first and third input files.
* sdiff and diff -y handle incomplete lines.


Major changes in version 2.0:

* Add sdiff and cmp programs.
* Add Texinfo documentation.
* Add configure script.
* Improve diff performance.
* New diff options:
-x --exclude
-X --exclude-from
-P --unidirectional-new-file
-W --width
-y --side-by-side
--left-column
--sdiff-merge-assist
--suppress-common-lines
* diff options renamed:
--label renamed from --file-label
--forward-ed renamed from --reversed-ed
--paginate renamed from --print
--entire-new-file renamed from --entire-new-files
--new-file renamed from --new-files
--all-text removed
* New diff3 options:
-v --version
* Add long-named equivalents for other diff3 options.
* diff options -F (--show-function-line) and -I (--ignore-matching-lines)
  can now be given more than once.
