Adds support for services which wrap other services.

This was required as if one wishes to add bundles, resources, etc. in a
generic fashion to a Dropwizard service in version 0.6.0 or later, one
needs to establish an AOP-style cutpoint on the abstract initialize and
run methods.
Merge pull request #228 from eonflare/add-generics-support-for-wrapped-services

Adds support for services which wrap other services.