Log Message:
Import cwdiff-0.2.6 as textproc/cwdiff.

cwdiff is a part of cj-overlay, and it has three modes, with
(textproc/) wdiff, diff, or without them, stand alone.

With wdiff or diff, it wraps output of those commands to
support directories and colorize the output.

  cwdiff -h or cwdiff --help
will tell you how to use it, and command line examples.