15158: ETHREEOH-2478: Fix mechanism that allows extension classpath override of subsystem instance properties and Spring config
- Reported broken on the forums
- Now improved unit test coverage
git-svn-id: https://svn.alfresco.com/repos/alfresco-enterprise/alfresco/HEAD/root@15160 c4b6b30b-aa2e-2d43-bbcb-ca4b014f7261