Support alias in baseClass configuration

[garthkerr]

If using the baseClass attribute where the class uses the same name as generated skeleton class, the model:build command produces an error:

[Propel\Generator\Exception\LogicException]
The class Data\App\User duplicates the class Data\Base\User and can't be used without alias

Configuring with baseClass="Data\App\User as AppUser" generates models successfully, but produces invalid code. Ideally, Propel would be able to automatically provide an alias (preferable), parse the aforementioned code block successfully, or provide another attribute like baseAlias etc.

[garthkerr]

Wrong version repository. Closing.