don't set items witch are not submitted from UA in content array on callback.

This is usefull if u want to process just subsets of a form e.g. by xajax

etemplate/inc/class.boetemplate.inc.php

@@ -634,6 +634,7 @@
 				{
 					return False;
 				}
+				if(!isset($pos[$idx])) return false;
 				$pos = &$pos[$idx];
 			}
 			return $pos;

etemplate/inc/class.uietemplate.inc.php

@@ -1677,6 +1677,7 @@
 					$attr = array();
 				}
 				$value = $this->get_array($content_in,$form_name,True);
+				if($value === false) continue;
 				
 				if (isset($attr['blur']) && $attr['blur'] == $value)
 				{