suzerain: #2665 add in-situ squared primitives

Adds rho^2, p^2, and T^2 from physical space (though rho^2
could be gathered in wave space as well).

Adds collection within app/perfect

Updates manual.gold tests to ignore the new entries.

git-svn-id: https://svn.ices.utexas.edu/repos/pecos/suzerain/trunk@44611 0bd85f0b-c151-43b9-a1e9-27231104551f