* gnu/services/desktop.scm (gvfs-service-type): New variable. (gvfs-configuration, make-gvfs-configuration, gvfs-configuration?, gvfs-package): New procedures. (<gvfs-configuration>): New record. * doc/guix.texi (Desktop Services): Document it. Change-Id: I584819500e2ce7d2b14e57dac238a96e9888e75e