Change from PR #552: rename setup_dependent_python_module -> setup_dependent_package

- Fixed in package.py
- Fixed wrong prototypes in packages that use it.
- Fixed build_environment to set module variables properly
  - added hacky fix to ensure spec/package consistency in build processes.
  - Need to think about defensive spec copy done by `Repo.get`.  May be
    time to think about an immutable spec implementation.

var/spack/repos/builtin/packages/mpich/package.py

@@ -54,7 +54,7 @@ def setup_dependent_environment(self, env, dependent_spec):
         env.set('MPICH_F90', spack_f90)
         env.set('MPICH_FC', spack_fc)
 
-    def setup_dependent_python_module(self, module, spec, dep_spec):
+    def setup_dependent_package(self, module, dep_spec):
         """For dependencies, make mpicc's use spack wrapper."""
         # FIXME : is this necessary ? Shouldn't this be part of a contract with MPI providers?
         module.mpicc = join_path(self.prefix.bin, 'mpicc')