Added some component files
add interfaces to PageInterface
add id to PageEntity
bundle config and mapping
remove parameters from PageFactory::create
move PageController to Bundle
move RoutableInterface into PageInterface

For services, `RoutableInterface` should always be an implementation of `PageInterface`, so the former is removed.
add Router constructor
add PageController service
add $config parameter to `AbstractExtension::postLoad`
add PageRouterSimpleLoader and Configuration
add loader and router in config
PageController now depends on PageRepository
remove unused boilerplate
add default page routing
filter disabled pages
add composer support for PageBundle
add specific documentation