Empty etag strings are parsed as NULL
Empty etag strings are parsed as NULL

Original git commit by Alexander Larsson <alexl@redhat.com> at 1185361340 +0200

svn path=/trunk/; revision=716

gicmo/gvfs,gicmo/gvfs,xkahn/gvfs-cmis,philipl/gvfs,xkahn/gvfs-cmis,halfline/gvfs,xkahn/gvfs-cmis,cpatulea/gvfs,halfline/gvfs,xkahn/gvfs-cmis,thiblahute/gvfs,thiblahute/gvfs,cpatulea/gvfs,philipl/gvfs,philipl/gvfs,halfline/gvfs,gicmo/gvfs,gicmo/gvfs