Added an option to allow default exception handler messages go to the

screen if necessary.

htdocs/config-dist.php

@@ -78,4 +78,8 @@ $cfg->log_environ_targets = LOG_TARGET_SCREEN | LOG_TARGET_ERRORLOG;
 // but probably only warnings are useful on a live site.
 $cfg->log_backtrace_levels = LOG_LEVEL_WARN | LOG_LEVEL_ENVIRON;
 
+// Makes debug backtraces go to the screen if the default exception
+// handler is called.
+$cfg->debug_mode = true;
+
 ?>