WFLY-3227 & WFLY-3540 batching changes

WFLY-3227 Replace batching="true|false" with <transaction mode="BATCH"/> in infinispan subsystem schema/model
https://issues.jboss.org/browse/WFLY-3227
WFLY-3540 Allow users to use web session clustering w/out batching
https://issues.jboss.org/browse/WFLY-3540

Requires custom operation transformer to handle cross-resource transformation.
Please merge https://github.com/wildfly/wildfly/pull/6449 first - this PR depends on those commits.