Python 3 support

[JNRowe]

Currently holding back Python 3 support are the following:

• argh, addressed in #31 and #33.
• kitchen, which is only used for i18n setup. Unfortunately upstream uses bzr, so adding Python 3 support is off the table.
• schematics, which shouldn't be a lot of work to support Python 3.

There are also a couple of places in hubugs itself that will need fixes, but they're mostly just five second changes.

[JNRowe]

• [x] argh is solved, either with aaargh or simple argparse
• [x] kitchen is removed in referenced branches
• [x] schematics is working if you use my fork, see j2labs/schematics#98

[JNRowe]

Closed by 23151fa6677c5b0008f5c32a2b2baf5b61eafcd1.