DbProviderFactories should be supported in app.config file for dbm.exe

[arviman]

I wasn't able to register the Mysql Data Provider whose config had been updated in the app.config of my project registered in PathToDll. Instead, I had to copy it to the DbProviderFactories section in the machine.config.

Would prefer to have a .config file that is used by dbm without a dependency to machine.config.