i3: use primary monitor for tray icons

Useful for multi-monitor and monitor + projector mode.
Also let xrandr set the first connected monitor as primary on login.

.i3/config

@@ -176,6 +176,7 @@ bindsym $mod+m mode "resize"
 # finds out, if available)
 bar {
         status_command i3status
+        tray_output primary
 }
 
 exec xautolock -locknow

.xinitrc

@@ -11,6 +11,9 @@ setxkbmap -layout "us,ru" -option "grp:caps_toggle,grp_led:caps,compose:ralt"
 xset dpms 610 610 610
 xset r rate 290 30
 
+# set primary output to the first connected monitor
+xrandr --output $(set -- $(xrandr | grep ' connected') && echo $1) --primary
+
 if [ -d /etc/X11/xinit/xinitrc.d ]; then
 	for f in /etc/X11/xinit/xinitrc.d/*; do
 		[ -x "$f" ] && . "$f"