Revert "Don't compress already-compressed files."

This reverts commit 190bffd846f044a13c239513f8ef1ea45ee8a1f2.

Created by  Eelco Dolstra  on July 1, 2013
GX2GISE2OZCIWPXYSDX7IEZDIMG6N2QJXMTVBVHQVZ6VFZBGZEIAC
Change contents