Widget\Limiter: show "all"

In case we pass limit=0 we show this, still unsure whether we should
provide a link for "showing all" - might really hurt with millions of
history rows.

library/Icinga/Web/Widget/Limiter.php

@@ -51,8 +51,10 @@ class Limiter extends AbstractWidget
             50 => '50',
             100 => '100',
             500 => '500'
-            // 0 => t('all')
         );
+        if ($currentLimit === 0) {
+            $availableLimits[0] = t('all');
+        }
 
         // if ($this->pages === 1 && $currentLimit === 10) return '';