Add in jboss-junit-configuration system property to scripts targets

The targets tests-scripts and tests-scripts-noserver make use of the XMLJUnitMultipleResultFormatter class to differentiate output between multiple runs of the same junit task:

<sysproperty key="jboss-junit-configuration" value="scripts"/>
<formatter classname="org.jboss.ant.taskdefs.XMLJUnitMultipleResultFormatter" usefile="${junit.formatter.usefile}" extension="-scripts.xml"/>

The first line is used by org.jboss.ant.taskdefs.XMLJUnitMultipleResultFormatter to define an extended name for the test class, and this causes the extended names to appear in the test reports.
The second line defines the formatter class but also causes the output for the test (i.e. TEST-org.jboss.test...) to be written to a file with an extended file name, ending in this example with -scripts.xml.

In the two test targets mentioned above, the system property was missing, so although the output was being written to distinct files, the test cases reports were not showing the differentaited output.

This jira issue adds in the missing system properties to $JBOSS_SRC/testsuite/build.xml