Gathers a few contributions

Gathers a few contributions that never made it into jokked repo
- Doctrine2 implementation
- 2 kind of Doctrine1 implementations: Doctrine seems better than
Doctrine1, but I don’t have the setup to confirm it, so I keep both
- Enhancement to Cache plugin : avoid missing array key error
- remove require_once
- updated Readme.md to explain usage
- replace Database by Doctrine2 in default plugins
- bump version from 1.6.2 to 1.6.3_dev
- updates composer.json to reflect contributions gathered here and make
this repo accessible to composer
Add Auth plugin as standard plugin
Adds cache cleaning capacity