Jboss deploymentfilerepository refactoring

Refactored jboss_deploymentfilerepository to use the Mixin lib/msf/http/jboss.
Using targets makes your mixin dependent of an ```Exploit``` because ```Auxiliary``` modules, for example, haven't targets. So I don't think it's a good idea to use try to use ```targets``` directly from the mixin. Just provide the JBoss related methods, useful to allow an exploit to do auto_target easily.