expect update to official classpathx release soon

When undeploying a datasource, use the new JProp.removeInstance() method in order to allow reload of the datasource properties file when the datasource will be reloaded.

Fix problems concerning undeployment of ROOT context webapps and management of several ROOT context wabpps having different hosts (fix bugs 304208, 300882)

Fixes bug #304880

Instead of linking/committin policy context at the end of the ear deployment, do the following :
deploy ejbs,
link EJBs and Web policy contexts,
commit EJBs policy context,
deploy wars,
commit web policy context.

Fixes bug #305023 and #305079