add simple import.py
Revert "Made globals a mutable hash."

This reverts commit 54ac00c81d74c1c936e3f2b5054a1ed3d83b1f59.
add module and import in builtins and python-lib; exec is not implemented
add exec-to-dict
add MetaModule
problems on exec-to-dict
revise MetaModule to contain env info
implement __import__, fix store error
remove MetaModule
clean
merge brown/master to my modules branch!
fix merge problem
merge Anand __import__ with mine
add macro to write built-in modules
merge Junsongs repo: add macro to write modules