* gnu/system/pam.scm (unix-pam-service): Add account and session PAM entries for pam-gnupg. Don't pass "#f" to "allow-root?" argument, because "lambda*" already does this by default. * doc/guix.texi (X Window): Document this. * gnu/services/xorg.scm (<slim-configuration>)[gnupg?]: New record field. (slim-pam-service): Pass "#:gnupg?" argument to "unix-pam-service".