[bio-tools] developer instructions and minor toolkit updates

[Titus Brown]

Hi all,

in honor of the forthcoming PyZine article (http://www.pyzine.com/), I've
revamped the Cartwheel Web site

	http://cartwheel.caltech.edu/

and added a rough'n'ready developer's section,

	http://cartwheel.caltech.edu/developers/

This section contains instructions for getting the most recent versions
of Cartwheel, FamilyRelations II, paircomp, and motility.

I've also added, updated, and/or corrected the build instructions for
the latter three distributions.

Please let me know if you have any trouble getting or compiling these
toolkits.  Also let me know if you want to take a look at the article
in advance of publication...

cheers,
--titus