Add support for Doctrine DBAL Query

|Q            |A       |
|---          |---     |
|Bug Fix?     |yes       |
|New Feature? |yes       |
|BC Breaks?   |no       |
|Deprecations?|no       |
|Tests Pass?  |yes |
|Fixed Tickets|GH-3    |

This adds Doctrine2 DBAL support, and fixes NativeQuery handling for ORM.

Todo:

* [x] DBAL WhereBuilder
* [x] Update documentation
* [x] Fix ConversionStrategy when only the field conversion is used.
* [x] Ensure enough testing coverage

Testing
* [ ] ParameterPrefix
* [ ] setEntityMapping (ORM)