Added a flatten option to make single relations (hasOne and belongsTo) able to have their data combined directly with the main entry instead of being server as a tree structure.

Made the relate() method protected as it should have always been.

Added a shorthand for bridge option in manyMany relations. Passing a string as options is now equivalent of passing as array with a bridge option.

->manyMany('table', array('bridge' => 'bridge_table'));
is now equivalent to:
->manyMany('table', 'bridge_table');
Fixed a bug that would cause empty models to have an id of 0 set in their data.