A number of minor fixes to problems that pychecker found.
# HG changeset patch
# User mark.williamson@cl.cam.ac.uk
# Node ID 55d38977b7f2e73b8c1090179928ac96c8922b90
# Parent b3bba126b04ab2f24274a1bcf5a224c6317c8e0d
A number of minor fixes to problems that pychecker found.
#header#
# HG changeset patch
# User #author#
# Date #date|date#
# Node ID #node#
#parent#
#desc#
#diff#