[Format] Trim all items elements

This removes unnecessary whitespace in output data

lib/Format.php

@@ -49,7 +49,8 @@ abstract class FormatAbstract implements FormatInterface{
     }
 
     public function setItems(array $items){
-        $this->items = $items;
+        $this->items = array_map(array($this, 'array_trim'), $items);
+
         return $this;
     }
 
@@ -105,6 +106,14 @@ abstract class FormatAbstract implements FormatInterface{
         // We leave alone object and embed so that videos can play in RSS readers.
         return $html;
     }
+
+    protected function array_trim($elements){
+        foreach($elements as $key => $value){
+            if(is_string($value))
+                $elements[$key] = trim($value);
+        }
+        return $elements;
+    }
 }
 
 class Format{