xauth still confused when a file exists with name of host

Commit 18a3c3a7 introduced some S_ISSOCK() checks, but only in gethost.c. Without corresponding checks in parsedpy.c, xauth can give very confusing results. In Debian bug #889720, I give a longer transcript of the transition from xauth-1.1 to xauth-1.1.1 to a fully fixed version on my hard disk.

Patch attached both there and here. xauth.parsedpy.patch