installer: Generalize desktop environments to system services.

* gnu/installer/services.scm (<desktop-environment>): Rename to...
(<system-service>): ... this.  Add a 'type' field.
(%desktop-environments): Rename to...
(%system-services): ... this.
(desktop-system-service?): New procedure.
(desktop-environments->configuration): Rename to...
(system-services->configuration): ... this.  Determine the base list of
services based on whether SERVICES contains at least one "desktop"
service.
* gnu/installer/newt/services.scm (run-desktop-environments-cbt-page):
Adjust accordingly.
* gnu/installer.scm (installer-steps): Likewise.

1 files changed, 1 insertions, 2 deletions

diff --git a/gnu/installer.scm b/gnu/installer.scm
index 5694cef66f7..50e2e7d85e0 100644
--- a/gnu/installer.scm
+++ b/gnu/installer.scm
@@ -256,8 +256,7 @@ selected keymap."
           (description (G_ "Services"))
           (compute (lambda _
                      ((installer-services-page current-installer))))
-          (configuration-formatter
-           desktop-environments->configuration))
+          (configuration-formatter system-services->configuration))
 
          (installer-step
           (id 'final)