mysql_schema_bulk_change 0.2.0

This extension to the MysqlAdapter in ActiveRecord enables bulk updates to schema definitions. Pr. default when calling connection#add_column the change will be executed a once, but Mysql allows for multiple changes to be executed in one SQL statement (http://dev.mysql.com/doc/refman/5.1/en/alter-table.html). The advantage of this is that it takes a lot less time, especially if the table is large.