Add support for Doctrine ORM

[alphalemon]

Add support for Doctrine ORM as alternative ORM to Propel

[ejkayani07]

+1. i would like AlphalemonCMS to have doctrine ORM

[alphalemon]

thanks :)

[alphalemon]

https://github.com/alphalemon/AlphaLemonCmsBundle/tree/doctrine-support

[ejkayani07]

thank you for doctrine support. i was waiting for this news.

[alphalemon]

@ejkayani07 I've just commited latest changes. At the moment the major work consist on query converting: would you like to give it a look and try to help me with this stuff? I'd really appreciate that!