PATCH: add new arguments to systemctl completion

["T.C. Hollingsworth" <tchollingsworth@xxxxxxxxx>]

This patch adds recently added arguments to systemctl that aren't in
the zsh completion script yet.

---
Index: Completion/Unix/Command/_systemctl
===================================================================
RCS file: /cvsroot/zsh/zsh/Completion/Unix/Command/_systemctl,v
retrieving revision 1.3
diff -u -r1.3 _systemctl
--- Completion/Unix/Command/_systemctl  21 Nov 2011 11:31:24 -0000      1.3
+++ Completion/Unix/Command/_systemctl  20 Dec 2011 23:45:59 -0000
@@ -43,6 +43,7 @@
     '--global[Enable/disable unit files globally]' \
     {-f,--force}'[When enabling unit files, override existing
symlinks. When shutting down, execute action immediately]' \
     '--defaults[When disabling unit files, remove default symlinks only]' \
+    '--root=[Enable unit files in the specified root
directory]:directory:_directories' \
     '*::systemctl command:_systemctl_command'
 }

@@ -73,8 +74,13 @@
     "status:Show runtime status of one or more units"
     "show:Show properties of one or more units/jobs or the manager"
     "reset-failed:Reset failed state for all, one, or more units"
+    "list-unit-files:List installed unit files"
     "enable:Enable one or more unit files"
     "disable:Disable one or more unit files"
+    "preset:Enable/disable one or more unit files based on preset
configuration"
+    "mask:Mask one or more units"
+    "unmask:Unmask one or more units"
+    "link:Link one or more units into the search path"
     "is-enabled:Check whether unit files are enabled"
     "load:Load one or more units"
     "list-jobs:List jobs"