python3: use format-source to run byteify-strings in .py files Using the format-source extension smooth out the pain of merging after auto-formatting. This change makes all of the Evolve test suite pass under python3 and has added benefit of being 100% automated using mercurial's `byteify-strings` script version 1.0 (revision 11498aa91c036c6d70f7ac5ee5af2664a84a1130). How to benefit from the help of format-source is explained in the README.

syntax: re
/figures/[^/]+\.png$
^html/
\.pyc$
~$
\.swp$
\.orig$
\.rej$
^tests/.*\.err$
^tests/easy_run.sh$
^build/
^dist/
^MANIFEST$
^docs/tutorials/.*\.rst$
\.ico$
tests/\.testtimes

^docs/training/graphs/
^docs/training/html/
^docs/training/index.html
^docs/training/graphviz-images/
^docs/training/img/
^docs/training/output/
^docs/training/pandocfilters/