- create a mode where no local files are accessed. (hmm, will
  that even block python library requests?... will need to
  whitelist that -- perhaps with generic whitelisting facility?)

- look through all modules to find holes... LOL.
  - os
  - os.path
  - shutil
  - tempfile
  - fnmatch
  - glob
  - stat 
  - pathclass (https://wiki.python.org/moin/PathClass)

- move to use `stub`... handles direct imports :)
  http://stub.readthedocs.org/en/latest/stubvsmock.html

- review the current file descriptor bridging mechanism... i think
  it makes assumptions on usage that may break the unusual use cases.
