ISPN-4516 Added Spring 4 support

Hi!

Please take a look at proposed solution for https://issues.jboss.org/browse/ISPN-4516

Implementation details:
* Spring 4 integration support added as separate module (spring/spring-4)
* Created copy of Spring 3 integration module + implemented missing methods from Cache interface (putifAbsent and get(Object, Class))

Why Spring 4 integration is implemented as a separate module?
* It is easier to introduce fixes and new features for specific Spring version
* Spring 4.1 will introduce many changes [1] which will not be backported to Spring 3
* At some point of time we may simply drop Spring 3 implementation and make Spring 4 our default

[1] http://spring.io/blog/2014/06/16/further-cache-improvements-in-spring-4-1

Best regards
Sebastian