Don't use nixUnstable
Merge remote-tracking branch 'origin/master' into systemd
Rewrite switch-to-configuration in Perl

This will make it more efficient to do systemd dependency graph
processing (if necessary).
Stop obsolete units, restart changed units, start new units
Initial version of a SpamAssassin service.

The configuration is expected to be managed by the user in /etc/spamassassin.
Only create the Apache user/group if it's "wwwrun"
Add services.httpd.fixUidAndGid option to assign reliable numeric UID and GID for the Apache user.

The option is disabled by default so that previously existing installations
aren't affected.

If you'd like to migrate to the fixed numeric id for Apache, set "fixUidAndGid
= true", edit the file "/etc/groups" and replace the old GID value with 54.
(NixOS can't do that for you because it refuses to change a GID that identifies
the primary group of a user.) Then run

  find / -xdev -uid $oldUID -exec chown 54 {} +
  find / -xdev -gid $oldGID -exec chgrp 54 {} +

to update ownership of all files that are supposed to be owned by Apache.
switch-to-configuration: Print all failed services
Merge pull request #21 from peti/assign-fixed-uid-and-gid-for-httpd-service

(Optionally) assign fixed a UID and GID for the user dedicated to running Apache.
Revert "Add services.httpd.fixUidAndGid option to assign reliable numeric UID and GID for the Apache user."

This reverts commit 0ef085d58a8307bfe6ba5a108a063a9e41a2549d.
Don't try to change the uid/gid of existing users

Unless we search the entire filesystem to do a chown *and* restart
existing processes owned by that user, there is no sensible way that
we can change uids/gids.  So don't try.
Assign uid/gid 54 to wwwrun
switch-to-configuration: Restart services that were manually started
spamassassin: call daemon with complete path
switch-to-configuration: Stop units in one call to systemctl
switch-to-configuration: Handle unit template instances
switch-to-configuration: Fix the call to install the boot loader
switch-to-configuration: Don't ellipsize log output
switch-to-configuration: Print new units
Allow overriding all NixOS tests to run with the minimal kernel possible for that test's config(s) (based on requiredKernelConfig)