suzerain: spec/def file naming

Moving to specification_foo.{cpp,hpp} from foo_specification.{cpp,hpp}.
Will do some namespace-related refactoring in subsequent commit.

git-svn-id: https://svn.ices.utexas.edu/repos/pecos/suzerain/trunk@43479 0bd85f0b-c151-43b9-a1e9-27231104551f