Search for assignment of the DOCUMENTATION variable in the given file.
    Parse that from YAML and return the YAML doc or None.

def get_docstring(filename, verbose=False):
    """
    Search for assignment of the DOCUMENTATION variable in the given file.
    Parse that from YAML and return the YAML doc or None.
    """

    doc = None

    try:
        # Thank you, Habbie, for this bit of code :-)
        M = ast.parse(''.join(open(filename)))
        for child in M.body:
            if isinstance(child, ast.Assign):
                if 'DOCUMENTATION' in (t.id for t in child.targets):
                    doc = yaml.load(child.value.s)
    except:
        if verbose == True:
            traceback.print_exc()
            print "unable to parse %s" % filename
    return doc