Const correctness on Java Collection Size.

I need to get rid of these, but cleaning them up first lets me
address them in-situ for const correctness _before_ I unravel
the runtime type maze.

lout/container.cc

@@ -121,7 +121,7 @@ Vector::~Vector()
    DBG_OBJ_DELETE ();
 }
 
-int Vector::size ()
+int Vector::size () const
 {
    return numElements;
 }
@@ -481,7 +481,7 @@ HashSet::~HashSet()
    delete[] table;
 }
 
-int HashSet::size ()
+int HashSet::size () const
 {
    return numElements;
 }