Use SIGUSR1 to thaw mpi processes, as SIGHUP has various meanings.
Use SIGUSR1 to thaw mpi processes, as SIGHUP has various meanings.

We also clean up mpi stuff before re-running bwc.pl

mancoast/cado-nfs,mancoast/cado-nfs,mancoast/cado-nfs,mancoast/cado-nfs,mancoast/cado-nfs,mancoast/cado-nfs,mancoast/cado-nfs