* gnu/services/avahi.scm (configuration-file): Use 'plain-file' instead
of 'text-file'.
(avahi-service): Turn into a regular procedure that returns a <service>.
* gnu/services/base.scm (root-file-system-service, file-system-service,
user-unmount-service, user-processes-service, host-name-service,
console-keymap-service, console-font-service, mingetty-service,
nscd.conf-file, nscd-service): Likewise.
(%default-syslog.conf): New variable.
(syslog-service): Use it. Turn into a regular procedure.
(guix-service, udev-rules-union, kvm-udev-rule, udev-service,
device-mapping-service, swap-service): Likewise.
* gnu/services/databases.scm (%default-postgres-hba,
%default-postgres-ident): Use 'plain-file' instead of 'text-file'.
(%default-postgres-config): Use 'mixed-text-file' instead of
'text-file*'.
(postgresql-service): Use 'program-file' instead of 'gexp->script'.
Turn into a regular procedure.
* gnu/services/desktop.scm (dbus-configuration-directory): Use
'computed-file' instead of 'gexp->derivation'.
(upower-configuration-file, geoclue-configuration-file,
elogind-configuration-file): Use 'plain-file' instead of 'text-file'.
(dbus-service, upower-service, colord-service, geoclue-service,
polkit-service, elogind-service): Turn into regular procedures.
(%desktop-services): Remove use of 'mlet' when iterating on
%BASE-SERVICES.
* gnu/services/lirc.scm (lirc-service): Turn into a regular procedure.
* gnu/services/networking.scm (static-networking-service,
dhcp-client-service, ntp-service, tor-service, bitlbee-service,
wicd-service): Likewise.
* gnu/services/ssh.scm (lsh-service): Likewise.
* gnu/services/web.scm (nginx-service): Likewise.
* gnu/services/xorg.scm (xorg-configuration-file): Use 'mixed-text-file'
instead of 'text-file*'.
(xorg-start-command, slim-service): Turn into regular procedures.
(xinitrc): Use 'program-file' instead of 'gexp->script'.
* gnu/system/install.scm (cow-store-service,
configuration-template-service): Turn into regular procedures.
* gnu/system.scm (other-file-system-services, device-mapping-services,
swap-services, essential-services, operating-system-services,
user-shells, operating-system-accounts): Remove now unnecessary
'mlet' and turn into regular procedures.
(operating-system-etc-directory, operating-system-activation-script,
operating-system-boot-script): Adjust accordingly.
* doc/guix.texi (Base Services, Networking Services, X Window, Desktop
Services, Database Services, Web Services, Various Services, Name
Service Switch): Adjust accordingly.