The attached patch enables libedit support in a generic way via configure.in, so I can pass in --with-readline=editline, --with-readline=readline, --with-readline=yes, or --with[out]-readline[=no] and it will do one of the following:

1. Enable editline support.
2. Enable readline support.
3. Enable default OS support (editline on OSX, readline otherwise).
4. Explicitly disable readline support.

Tested functional via cmd.py and with basic poking around via the readline module.

The attached patch was created against the 2.7 branch, but I'll produce a patch against 'trunk' sometime later on this week.

PS. The only quirk I found was the fact that FreeBSD 9's libedit lied when it reports the number of available history items. Hrmmm..