localizer 5.x-3.7

Drupal coding standards fixes.
Code optimization.
Less memory used.
Path module compatibility (Sponsored by LucksDigital).

The two localizer attributes added to the node object have changed name :
$node->pid is now $node->localizer_pid
$node->language is now $node->localizer_language

This has been changed only in the code and NOT in the database.
The database's fields are yet pid and language.