Refactor web to silex

Closes #55

* Added pagination. Refactored to use DBAL, as required for the pager.
* Added a show more button to hide version when there's too many.
* By default, only the dev-trunk version and the last three version are shown.
* Added an active only / all filter.
* Added .htaccess.
* Now uses Knp ConsoleServiceProvider to wrap the console Application.
* Commands, assets and the bootstrap were moved for a leaner filestructure.
* Now uses Doctrine DBAL instead of PDO directly.
* The DatabaseProvider was replaced by DoctrineServiceProvider.
* Changed default filter to all plugins and order by last_committed when no query.
* Misc cs fixes