Revert "allowed to pass filter objects to the configurator"

This reverts commit a9b4debe37370a4ff30141f8e4c6a444c226e06c. See the
discussion on the original PR:

https://github.com/doctrine/doctrine2/pull/434

Conflicts:
	lib/Doctrine/ORM/Configuration.php
[DDC-2019] Add support for expression in QueryBuilder#addOrderBy()
Add php 5.5 to the build matrix (travis)