Added infinispan persistence modules

Hi Marian, 

Here's the pull request we talked about. Not everything compiles in the jbpm-infinispan-persistence module: the tests refer to an "AbstractRuleBase" which has probably be replaced with a KieRuleBase or whatever. I also made sure that they use logback for logging, instead of log4j: Geoffrey recently moved all projects to logback. 

Lastly, I saw that there were still a few TODO's left: if you could fix those, that would be great. At the very least, if you don't have time to fix them, please add as much description (comments) as possible where the TODO's are, so that other developers will know what should be done there, or what the issue is. 

Thanks!