ISPN-5007 ISPN-5008 Enhance the distribution script to detect missing artifacts

Replace &lt;fileset/&gt; with &lt;file/&gt; to have the script fail when the source files are missing.
Fix missing cachestore-remote and extended-statistics modules.

https://issues.jboss.org/browse/ISPN-5007
https://issues.jboss.org/browse/ISPN-5008