JDF-639 Converted the JAX-RS resource classes to SLSBs.

This now ensures that the root-resource classes now comply with
the requirements outlined in JAX-RS 1.1, namely that JAX-RS
providers supporting EJBs allow SLSBs as root resource classes
(with no mention of SFSBs).

Since JAX-RS root-resource classes are request-scoped by default,
the CDI RequestScoped annotation is redundant and thus removed.

Also removed unused imports.