
This fix checks the PVM launcher environment var CHPL_MULTIREALM_LAUNCH_DIR.

This fix checks the PVM launcher environment variable
CHPL_MULTIREALM_LAUNCH_DIR to make sure it is set. If not, the launcher
uses CHPL_HOME as its base. Before this fix, an unset variable (easy to
overlook) would cause a launch segfault.



git-svn-id: 88467cb1fb04b8a755be7e1ee1026be4190196ef@15735 3a8e244f-b0f2-452b-bcba-4c88e055c3ca

hildeth/chapel,CoryMcCartan/chapel,sungeunchoi/chapel,hildeth/chapel,CoryMcCartan/chapel,CoryMcCartan/chapel,sungeunchoi/chapel,hildeth/chapel,sungeunchoi/chapel,chizarlicious/chapel,hildeth/chapel,CoryMcCartan/chapel,sungeunchoi/chapel,CoryMcCartan/chapel,hildeth/chapel,sungeunchoi/chapel,hildeth/chapel,hildeth/chapel,chizarlicious/chapel,sungeunchoi/chapel,sungeunchoi/chapel,chizarlicious/chapel,CoryMcCartan/chapel,CoryMcCartan/chapel,chizarlicious/chapel,chizarlicious/chapel,chizarlicious/chapel,sungeunchoi/chapel,chizarlicious/chapel