[Libguestfs] [PATCH v2 0/4] sysprep: Remove various backup files.

In v2: - The backup-files operation now operates on a conservative whitelist of filesystems, so it won't touch anything in /usr. Consequently it also runs much more quickly, about 4 seconds on the barebones virt-builder fedora-25 image. - Call Gc.compact () in visit_tests. - Added documentation to fnmatch.mli.