Provide CDI (JSR-299) support out-of-the-box

This is a proposal to have the ModeShape JCR library natively support CDI (JSR-299). The Seam JCR module already provides extremely useful CDI integration for ModeShape and Jackrabbit. But the Seam team advocates that projects "provide CDI integration directly from their own projects". It is in this vein that we should seriously consider doing this.

The first step would be to enable clients to inject javax.jcr.Repository and/or javax.jcr.Session instances. Because Seam JCR supports ModeShape 2.x, the ModeShape configuration needed to be injected. While this definitely can continue, there's also room for improvement on the ModeShape side to make this easier. With our changes to configuration for 3.0 (including a minimal configuration with sensible defaults, and each configuration is now for a single repository) and our integration with JBoss AS 7, it's quite possible that only the repository name need be used; for other application servers and environments, it still should be possible to inject the JSON configuration for the repository. Either way, this should get easier for client code.

Other options are possible, but again we need to coordinate and work with the Seam JCR project to ensure a clean transition and to align plans and roadmaps.