handle most of the language syntax yet)
create NestedCodeGenerator used to generator the separate code object
that needs to be passed as an argument to MAKE_FUNCTION when a def
stmt is found (probably useful for class too)
change CodeGenerator.visitFunction to use the NestedCG
add CompiledModule class to handle creation of .pyc (pretty minimal
for now)
add makeCodeObject method to PythonVMCode that replaces symbolic names
with indexes into slots of the code code. the design of this
class will probably need to be revised.
compile.py: ASTVisitor framework plus bits of a code generator that
should be bug-for-buf compatible with compile.c
misc.py: Set and Stack helpers
test.py: a bit of simple sample code that compile.py will work on
