WFLY-3715 Async servlets cause lock timeouts for distrubutable sessions

https://issues.jboss.org/browse/WFLY-3715

Adds 2 new modules: org.wildfly.clustering.ee.spi and org.wildfly.clustering.ee.infinispan
These modules contain logic common to org.wildfly.clustering.ejb.spi and org.wildfly.clustering.web.spi; and org.wildfly.clustering.ejb.infinispan and org.wildfly.clustering.web.infinispan, respectively.