Properly set classpath for valid JAXWS Provider resolution in binary distro testsuite

The binary distro testsuite is run through Ant and relies on the configured java.endorsed.dirs + classpath for correctly selecting the JAXWS Provider impl.
On JBossWS-CXF, the javax.xml.ws.spi.provider service is configured both in cxf-rt-frontend-jaxws.jar and jbossws-cxf-factories.jar. The latter (jbossws conf) needs to either come first in the classpath or be in java.endorsed.dirs.
Given AS7 does not come with an explicit folder for endorsing, properly set java.endorsed.dirs env implies the same knowledge as sorting the entries in the Ant classpath (AS7 relies on modules for preventing this; but users can use that for in-container clients only). Hence we should sort the classpath in the jbossws-cxf binary testsuite so that jbossws-cxf-factories.jar comes before cxf-rt-frontend-jaxws.jar.