Added MySQL 3.23/4.0/4.1 compatibility
Added MySQL 3.23/4.0/4.1 compatibility

* Updated SQL introspection queries to use syntax compatible with
  older versions of MySQL
* Updated table/column escaping and quoting to be more DRY
* Updated DO driver dependencies to 0.9.9
* Fixed specs that were broken with MySQL

[#689 state:resolved]

datamapper/dm-postgres-adapter