put wmii in a loop cause it crashes once or twice a month

This also let's you change orientation. See comments

svn path=/nixos/branches/modular-nixos/; revision=15412

upstart-jobs/xserver/windowManager/wmii.nix

@@ -22,13 +22,23 @@ mkIf cfg.enable {
 
   services = {
     xserver = {
-
+      # stop wmii by
+      #   $wmiir xwrite /ctl quit
+      # this will cause wmii exiting with exit code 0
+      #
+      # why this loop?
+      # wmii crashes once a month here. That doesn't matter that much
+      # wmii can recover very well. However without loop the x session terminates and then your workspace setup is
+      # lost and all applications running on X will terminate.
+      # Another use case is kill -9 wmii; after rotating screen.
+      # Note: we don't like kill for that purpose. But it works (-> subject "wmii and xrandr" on mailinglist)
       windowManager = {
         session = [{
           name = "wmii";
           start = "
-            ${pkgs.wmiiSnap}/bin/wmii &
-            waitPID=$!
+            while :; do
+              ${pkgs.wmiiSnap}/bin/wmii && break
+            done
           ";
         }];
       };