hdf5doc

_ This file contains the work I did in early 2011 on 
the Groups chapter to turn it into the Groups and Links
chapter. I wasn't able to finish the work. It is likely
I won't be able to work on it for awhile. Along with 
this change, I will copy the 1.8 version of 
09_GroupsAndLinks.html to the trunk version. I am 
working on a description of external links that i want 
to add to the Groups chapter.