rest_version

This is an absolute first stab at getting a stable integration for a versionable rest based on the drupal core module.
Note that the development is currently on github for the time being.

https://github.com/SurangaPG/rest_version

WIP concepts

The actual versions:
- Config/Plugin logic like a lot of the core implementations. With a major version, namespace (for the plugins)

RestResource handling:
- Assume a plugin as core rest. But instead of using the "default" plugin manager a more granular approach is used via a factory service. This will generate a more on the fly approach based on the namespace of the detected versions.
Discussion point:
Apparently a plugin manager also looks in the "associated" namespaces (odd because I tested it beforehand and it didn't seem to work).
E.g: PluginRest esourcev0ResourceClass and Rest esourcev1ResourceClass can potentially be detected by a single manager.
This has the advantage of being less fragmented, but the disadvantage of requiring extra logic to filter out any resources that don't have a "version" plugin.