Fixes JENKINS-21332 https://issues.jenkins-ci.org/browse/JENKINS-21332
* Moved fortifyclient-{version}.jar files to WEB-INF/fortify-lib/
* adjusted FortifyClientClassloader to load from pluginWrapper.getBaseUrl("WEB-INF/fortify-lib/fortifyclient-" + version + ".jar");
* adjusted test (needs Jenkins Test Harness now - only works with plugin loaded)

Signed-off-by: Martin Kutter <martin.kutter@fen-net.de>