DAOs created on 4.7.11 (and up) cannot be used on previous versions

I was doing some tests with CiviHR and CiviCRM 4.7.13 and I stumbled on a Backward compatibility problem. It was introduced by this PR https://github.com/civicrm/civicrm-core/pull/8769, and, basically, it makes impossible to use DAOs generated in CiviCRM 4.7.11 (and newer) on previous versions. This is due to the fact that the generated code will make calls to CRM_Core_DAO_AllCoreTables::getImports(), CRM_Core_DAO_AllCoreTables::getExports() and CRM_Core_DAO_AllCoreTables::invoke() which don't exist prior to 4.7.11.

This is a big problem for extensions using its own DAOs (we have A LOT of them for CiviHR). If we start using starting from CiviCRM 4.7.11 for development we'll have to stop supporting any previous version (or we'll have to maintain two separate builds, but that seems a bit too much for a minor version upgrade)