Incorrect path in build.properties

Sorry if you don't really want a JIRA on this, but the path on the install documentation and the ant build is wrong and causes it to break.

The path on the documents and ant.properties is jBPM.url=http://hudson.jboss.org/hudson/job/jBPM5/lastStableBuild/artifact/target

I think the correct one is
jBPM.url=http://hudson.jboss.org/hudson/job/jBPM5/lastSuccessfulBuild/artifact/jbpm-distribution/target/

This isn't the end of the world, but might slow down a lot of people when they try to get started for the first time.