mpiexec-0.79 compile problem on OS X

[Glen Beane]

SA_NOMASK is not defined on OS X  (not POSIX standard?)

adding this to mpiexec.h works (I think):

#ifndef SA_NOMASK
#define SA_NOMASK	SA_NODEFER
#endif



on linux SA_NOMASK seems to be defines at SA_NODEFER