suzerain: #3018 add implied else keyword

Dodgy the way I had that originally written.

git-svn-id: https://svn.ices.utexas.edu/repos/pecos/suzerain/trunk@43097 0bd85f0b-c151-43b9-a1e9-27231104551f
suzerain: #3018 fix off-by-one in bracket search

I was interpolating from one interval to the right, which failed
when the last interval was selected.  This interpolates from the
correct bracket.  Origin of the bug was named it 'lit' when it
wasn't the lower bounding iterator for the bracket.  Oops.

git-svn-id: https://svn.ices.utexas.edu/repos/pecos/suzerain/trunk@43098 0bd85f0b-c151-43b9-a1e9-27231104551f