ISPN-3974 Make it compile with JDK8

* Module name calculation in javascript driven Server/AS/Wildfly
now works with both JDK7 and JDK8 by trying a split/join and if it
does not work, use a replace.
* spliterator() method name clashes with a new spliterator() method
introduced in java.util.Collection for JDK8, so name it differently
* Enable animal-sniffer maven plugin only when JDK7 is used since
it does not yet work with JDK8 (not even latest version 1.10).
ISPN-3885 Non-Tx Cross Site optimizations

* clear() and putAll() methods remain unchanged
* fixed a link and a list in the x-site documentation
* split the non-tx backup interceptor in two to allow sending the
rpc for the backup nodes and backup sites concurrently