Restore the "do-not-launch" functionality so users can test a mapping without launching it.
Add a "do-not-resolve" cmd line flag to mpirun so the opal/util/if.c code does not attempt to resolve network addresses, thus enabling a user to test a hostfile mapping without hanging on network resolve requests.
Add a function to hostfile to generate an ordered list of host names from a hostfile
This commit was SVN r18190.
