Improving BSD licensed text processing tools

[Jesse Hagewood]

Last week, I was able to finish .gz support in sdiff and diff. zsdiff, but
zdiff is outputting the diffs differently than the existing zdiff.
Dag-Erling pointed out in an email yesterday the problems with my
decompression, and how it should be properly implemented. Even though SoC
is finished, this is still something I'd really like to see finished.

I also wrote man files for zdiff and zsdiff, but Dag-Erling suggested that
using symlinks to the diff and sdiff man pages would be a better idea.

I've also completed my final evaluation for Google.

Finally, thank you all for giving me the chance to participate in SoC. My
project this summer has been a great learning experience.