[WFCORE-400] : Remove <any-ipv4-address/> and <any-ipv6-address>.

Removing usage of any-ipv4-address and any-ipv6-address.
Only any-address + preferred IP stack system property is supported.

Jira: https://issues.jboss.org/browse/WFCORE-400
I should have commented a bit on this when I wrote the code, as the preferIPv6Stack var name can confuse readers. I basically deliberately abused the java.net.preferIPv6Addresses property and treat it as indicating a user preference for IPv6, i.e. as if it *were* a "java.net.preferIPv6Stack" property. But I only hack that way if they haven't set java.net.preferIPv4Stack=false.

This is a local var name though, and its name reflects how it is used. The new PREFER_IPV6_STACK in InetAddressUtil is public API.