Configurable list of import names to hide from tracebacks

[dag]

Using something like,

dict((os.path.abspath(mod.__file__), name)
    for name, mod in sys.modules.iteritems()
    if hasattr(mod, '__file__'))

we can map files to modules, and use that to match lines in tracebacks against a 'blacklist' of module globs to hide. Use internally for traceback cleaning and maybe expose publicly if it seems useful.