Extensions to spring-batch's retry framework.

In particular, this adds the following capability:

1.  Support for the Callable class within the ExtendedRetryTemplate
2.  A Classifier instance which is based on guava predicates
3.  Some useful predicates
4.  A retry policy which is based on a generic exception classifier, rather than the existing SimpleRetryPolicy which assumes a Map based approach to determining exception classification.
Adding the RetryTemplate annotation and associated RetryTemplateAspect.

This will allow us to annotate method calls, and lookup the requested RetryTemplate
instance from the spring context, and enclose the method call inside the retry loop.
Merge branch 'master' of github.com:mattinger/jrugged