better handling of using directives

Examples/test-suite/python/using_member_runme.py

@@ -0,0 +1,10 @@
+from using_member import *
+
+b = B()
+assert b.get(int(1)) == 10
+assert b.get(float(1)) == 20
+
+bb = BB()
+assert bb.greater(int(1)) == 0
+assert bb.greater(float(1)) == 1
+assert bb.great(True) == 2