Create an include/mpeu directory even if it is empty

* Each library having an include directory means that the pkgconfig
  file is consistent and avoids users of oasis3 receiving missing
  directory errors.

packages/oasis3-mct/package.py

@@ -194,15 +194,13 @@ def build(self, spec, prefix):
 
     def install(self, spec, prefix):
 
-        mkdirp(prefix.include.mct)
-        # The directory name has a '.', so create the path manually:
-        mkdirp(join_path(prefix.include, "psmile.MPI1"))
-        mkdirp(prefix.include.scrip)
         mkdirp(prefix.lib.pkgconfig)
 
         src_dst = []
         for libname in self.__libs.keys():
 
+            mkdirp(join_path(prefix.include, libname))
+
             for f in [ self.__libs[libname]["filerelpath"],
                        self.__libs[libname]["pcrelpath"] ]:
                 src_dst.append( (join_path(self.__builddir, f),