Committed at r22695. Couple of notes:

* We don't use tabs in variable assignments (e.g. a = b).
* &(struct->member) isn't necessary, &struct->member works. It's not a
big deal though; we all tend to overuse params at times.

Other then that, great job! Much better then I expected. I'm also curious as to why you had fs and fm variables instead of just f. The current "standard" is to use single-
letter variable names for topological elements, but multiple two-letter variables might
be a better idea (at the very least, they differentiate different uses of data, even if
the actual meaning of the second letter isn't obvious).