Use OPENSHIFT_*_DIR in standalone.conf

In the JBoss cartridges' standalone.conf file, use OPENSHIFT_JBOSSAS_DIR
or OPENSHIFT_JBOSSEAP_DIR as appropriate to set the value of CART_DIR.
Merge pull request #3055 from Miciah/update-CART_DIR-in-standalone.conf

Merged by openshift-bot