[WIP] ResourceBundle

This bundle aims provides *object* resource location services based on [Puli](https://github.com/puli/puli).

Note that I will break a component out of this bundle, but its just easier to do the initial development as a bundle.

Examples:

- **Static document path mapping**: Map the path `/routes` to `/cms/routes`
- **Dynamic document resolution**: Map the path `/routes` to `/cms/<current site>/routes`.
- **Access documents at a static location**: Map `/role/menu/main` to `/cms/menus/main-menu`.
- **Cascading document resource resolution**.

The first example could use the existing CMF base route configuration to
resolve paths.

The benefit of the next two examples would be most strongly felt in
association with another component which would provide a context for the
document resource resolution.

For example, a `Site` which is matched against the incoming hostname would
provide the context with which to resolve the documents.

Problems which this aims to solve:

- Resource location by immutable paths.
- Contextual (e.g. per site) document location

Things it would make possible:

- Browsing composite content repositories (e.g. you could "mount" a Doctrine ORM repository at a given path, and the PHPCR repository at another path)
- Acting as a "virtual filesystem" for **tree browser** implementations
- Globbing in the PHPCR Shell

See: 

- https://github.com/symfony-cmf/symfony-cmf/issues/212 for discussion that led to this.
- https://github.com/puli/puli/issues/11 discussion on puli
what would the path be relative to?