add support for calling named function variables

in _examples/funcs/test.py

```Python
# TODO: not currently supported:

# print("funcs.F1()...")
# f1 = funcs.F1()
# print("f1()= %s" % f1())
#
# print("funcs.F2()...")
# f2 = funcs.F2()
# print("f2()= %s" % f2())
#
# print("s1 = funcs.S1()...")
# s1 = funcs.S1()
# print("s1.F1 = funcs.F2()...")
# s1.F1 = funcs.F2()
# print("s1.F1() = %s" % s1.F1())
#
# print("s2 = funcs.S2()...")
# s2 = funcs.S2()
# print("s2.F1 = funcs.F1()...")
# s2.F1 = funcs.F1()
# print("s2.F1() = %s" % s2.F1())
```

I can't remember at this point what the issue(s) are but presumably there is nothing fundamental from preventing this from working.

Start with _examples/funcs/test.py and inspect the commented calls for funcs.F1, funcs.F2, funcs.S1, and funcs.S2. Run the example to establish its current behavior; done means the shown named-function-variable calls can be enabled and execute successfully.

Written by the indexing model from the issue text.