units: exclude gettys from isolate requests

gettys are nowadays mostly autospawned and hence usually subject to
being shut down on isolate requests, since they are no dependency of any
other unit. This is a bad idea if the user isolates between
multi-user.graphical and graphical.target, hence exclude them from the
isolation.

This has the effect that gettys no longer cleaned up when
emergency.target is isolated, which might actualy be considered a
feature, even though it is a change from previous behaviour...

Note that the one getty that really matters (the one on tty1) is still
removed when isolating to emergency.target since it conflicts with
emergency.service.

TODO

@@ -17,6 +17,8 @@ Bugfixes:
 
 Features:
 
+* place start-pre/start-post/... scripts in sub cgrouprs
+
 * Make RuntimeWatchdogUSec= property writable
 
 * start polkit agent in systemctl, similar to the password agent, to allow
@@ -100,8 +102,6 @@ Features:
 
 * add option to sockets to avoid activation. Instead just drop packets/connections, see http://cyberelk.net/tim/2012/02/15/portreserve-systemd-solution/
 
-* isolate for getty is still broken, due to logind
-
 * default unix qlen is too small (10). bump sysctl? add sockopt?
 
 * support units generated by a generator and placed in /run/systemd/system/; the directory is

units/getty@.service.m4

@@ -32,6 +32,7 @@ After=rc-local.service
 # sure that this is synchronized before getty.target, even though
 # getty.target didn't actually pull it in.
 Before=getty.target
+IgnoreOnIsolate=yes
 
 [Service]
 Environment=TERM=linux

units/serial-getty@.service.m4

@@ -32,6 +32,7 @@ After=rc-local.service
 # sure that this is synchronized before getty.target, even though
 # getty.target didn't actually pull it in.
 Before=getty.target
+IgnoreOnIsolate=yes
 
 [Service]
 Environment=TERM=vt100