Improve BSD licensed text-processing tools

[Jesse Hagewood]

Last week I started taking a look at sdiff, here is the progress that I've
made so far:

- Completed a test script for all options.
- Fixed the default spacing between the left and right columns in output to
match GNU sdiff's.
- Fixed a problem with some inconsistent spacing in the right column of
output when --width was specified. Now has consistent indentation on the
right side for any width.
- Completed the --help option.
- The man page for BSD sdiff was lacking a lot of information, so I
completed it.

For the most part, there doesn't seem to be much left to do with sdiff
except fix a few scattered bugs. In Ben Fiedler's 2010 SoC wiki page, the
only TODO he had left for sdiff was to pass the diff-specific args in sdiff
to a diff process. This is working for all diff-specific options right now
except for -W, which when passed to diff, thinks it is -w and exits with an
error. Today I will try to fix this bug. I will also begin testing BSD
sdiff together with BSD diff to see if everything works fine, since sdiff
calls whatever diff is in /usr/bin, which has been GNU diff for me.

I will probably spend the majority of the week working on what I have left
to do in diff, unless I can find any more work to be done in sdiff.

Google's evaluations are also this week, so I will fill that out once it is
posted today on the GSoC site.