now in the term field appear also the new terms

by default get_terms only return the terms who have at least one
post created, adding a argument for return also the new terms

this fixes magic-fields-team#146

field_types/term_field/term_field.php

@@ -63,7 +63,7 @@ public function display_field( $field, $group_index = 1, $field_index = 1 ) {
     }
 
     $option_from_term_array = $field['options']['term'];
-    $options = get_terms($select[$option_from_term_array]);
+    $options = get_terms($select[$option_from_term_array], array('hide_empty' => false));
     $output = '<div class="mf-dropdown-box">';
     $value = $field['input_value'];