Prison release date: Our file of partial and completed forms is fat. A full drawer. We created the form, for convenience sake, way back when, possibly when Ald. Paul Wigoda was convicted of bribery in 1974. But it’s hard to be sure. We do periodic purges to make room for new, completed forms. On Thursday, we added Ald. Carrie Austin to the file. She’s the latest alderman to run afoul of the law, allegedly, and, truth be told, we’re more disappointed than usual. Editorials Not that we didn’t see it coming. Austin had been under federal investigation for more than two years. And if you understand Chicago, you understand never to be shocked when an alderman, even a super reform type, is caught out. Remember Larry Bloom?