Issue #134 :returning_id column should be of type Column.

Using rails 3.2.9 and this gem v1.4.1.

Feb 11, 2011 ActiveRecord LogSubscriber was changed to log the bind parameters, and assumes "binds" passes an AR Column object (or something that implements the "name" method).

So instead of a symbol :returning_id it should pass an instance of OracleEnhancedColumn.

Attached patch fixes this.