Don’t use a default setting for 'order'

This will make i3status depend on a useful configuration file (so
/etc/i3status.conf has to be installed) to actually output anything.

However, it fixes a very common error: people edit their i3status.conf and
don’t get that the first order directive has to use =, not +=. Since order is
now empty by default, you can use += everywhere.

i3status.c

@@ -253,7 +253,7 @@ int main(int argc, char *argv[]) {
         };
 
         cfg_opt_t opts[] = {
-                CFG_STR_LIST("order", "{ipv6,\"run_watch DHCP\",\"wireless wlan0\",\"ethernet eth0\",\"battery 0\",\"cpu_temperature 0\",load,time}", CFGF_NONE),
+                CFG_STR_LIST("order", "{}", CFGF_NONE),
                 CFG_SEC("general", general_opts, CFGF_NONE),
                 CFG_SEC("run_watch", run_watch_opts, CFGF_TITLE | CFGF_MULTI),
                 CFG_SEC("wireless", wireless_opts, CFGF_TITLE | CFGF_MULTI),
@@ -307,6 +307,9 @@ int main(int argc, char *argv[]) {
         if (cfg_parse(cfg, configfile) == CFG_PARSE_ERROR)
                 return EXIT_FAILURE;
 
+        if (cfg_size(cfg, "order") == 0)
+                die("Your 'order' array is empty. Please fix your config.\n");
+
         cfg_general = cfg_getsec(cfg, "general");
         if (cfg_general == NULL)
                 die("Could not get section \"general\"\n");

i3status.conf

@@ -3,7 +3,7 @@ general {
         interval = 5
 }
 
-order  = "ipv6"
+order += "ipv6"
 order += "disk /"
 order += "run_watch DHCP"
 order += "run_watch VPN"

man/i3status.man

@@ -51,7 +51,7 @@ general {
         interval = 5
 }
 
-order  = "ipv6"
+order += "ipv6"
 order += "disk /"
 order += "run_watch DHCP"
 order += "run_watch VPN"