Autotools2

Don't merge. This is a mess of changes. I'm putting this here because I promised Kevin I would.

Trying to implement autotools packaging in terms of setup.py. So far so good.

* `make build` works
* `make install` works
* `make distcheck` fails
* `make uninstall` fails
* `make clean` doesn't seem to work

There are several new developer tools in `bin/`.

`mt-clean` now takes a `-A` option, meaning all. Be careful with it. It deletes files that git is not tracking or is ignoring. Without this option it only deletes ignored (which is pretty safe).

I finally deleted `old/`.

I just noticed that it clobbers Kevin's update to `bin/mt-gen-mousetrap.po`. We'll want to bring that back.