Include pydebug interpreters

[natefoo]

Binary objects built on a CPython that's built with Pydebug (--with-pydebug) are incompatible with objects built on non-pydebug CPythons (this is the d in PEP 425 tags). The software I work on for my day job has a pretty big list of slow-to-build C extension dependencies, and on the occasions that I need to use Pydebug while working a problem, it'd be handy to have prebuilt wheels around that are kept up to date by our wheel building automation.

Pydebug builds shouldn't be included in the standard image so as to keep the image size down, but we could build a separate image that included them.

Thoughts?