Modified start_test such that it maintains settings for CHPL_COMM and uses the util/comm.pl script to set this environment variable.  This makes it easier to use start_test with, for example, gasnet.
Modified start_test such that it maintains settings for CHPL_COMM and
uses the util/comm.pl script to set this environment variable.  This
makes it easier to use start_test with, for example, gasnet.


git-svn-id: 88467cb1fb04b8a755be7e1ee1026be4190196ef@12956 3a8e244f-b0f2-452b-bcba-4c88e055c3ca

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