Adding base tag plugin and changing relative bundle paths

- adds a `base.tag` tag handler that all apps need to use
- all requests are now relative to the path generated by the base tag plugin
- unbundled resources requests can be now be unversioned which means the default app doesnt need to use the versioned content path tokens
- removes the need for `/static` to be applied to all unversioned bundle requests
- replaces the `AppVersion` and `BundlePath` service with a `AppMeta` service that provides access to app info like the locales, locale cookie and app version.