+
+ // If $a->config[$family] has been previously set to '!<unset>!', then
+ // $a->config[$family][$key] will evaluate to $a->config[$family][0], and
+ // $a->config[$family][$key] = $value will be equivalent to
+ // $a->config[$family][0] = $value[0] (this causes infuriating bugs),
+ // so unset the family before assigning a value to a family's key
+ if($a->config[$family] === '!<unset>!')
+ unset($a->config[$family]);
+