Include original entity when saving FPP

Typically entities - at least Nodes - will include an "original" property. This contains the unchanged entity loaded directly from the database, see entity_load_unchanged()

Here's what the Node module does on node_save()

<?php
    // Load the stored entity, if any.
    if (!empty($node->nid) && !isset($node->original)) {
      $node->original = entity_load_unchanged('node', $node->nid);
    }

    field_attach_presave('node', $node);
    global $user;

    // Determine if we will be inserting a new node.
    if (!isset($node->is_new)) {
      $node->is_new = empty($node->nid);
    }
?>

Patch incoming to replicate this process.