Add jaxp.properties file to jaxws-retail quickstart for JDK 8 requirements

From https://bugzilla.redhat.com/show_bug.cgi?id=1013502#c16

rsearls described this issue:

In JDK 8, wsconsume (org.jboss.ws.plugins:maven-jaxws-tools-plugin)
requires the presence of ${SOMEPATH}/jdk1.8.0_05/jre/lib/jaxp.properties,
contents javax.xml.accessExternalSchema = all
(see http://docs.oracle.com/javase/7/docs/api/javax/xml/XMLConstants.html#ACCESS_EXTERNAL_SCHEMA
http://stackoverflow.com/questions/23011547/webservice-client-generation-error-with-jdk8)

For quickstart jaxws-retail the user needs to be informed they require
this file. How should I handle this? Provide jaxp.properties in the
quickstart and document this in the README?