ISPN-5007 Enhance the distribution script to detect missing artifacts
ISPN-5008 7.0.x missing cachestore-remote and extended-statistics modules

Replace <fileset/> with <file/> to have the script fail when the source files are missing.
Fix missing cachestore-remote and extended-statistics modules.
Implement purgeOnJoin

The joiner will still do the preload, but the entries will be removed from
the data container.

Also includes a fix for ISPN-3217 (entries not written to the cache store
on a backup owner with CACHE_MODE_LOCAL).

A hack was needed to avoid triggering ISPN-3443 (state transfer undoing the
remove operations).