suzerain: grammar/clarity

git-svn-id: https://svn.ices.utexas.edu/repos/pecos/suzerain/trunk@42729 0bd85f0b-c151-43b9-a1e9-27231104551f
suzerain: #2503 remote p1 from radial_nozzle

Also, updates Doxygen and percolates the solver API
changes throughout the tests and applications directory.

git-svn-id: https://svn.ices.utexas.edu/repos/pecos/suzerain/trunk@42730 0bd85f0b-c151-43b9-a1e9-27231104551f