Avoid alignment issues in opal_value_t copies

cmr=v1.8.2:reviewer=rhc
Resolve race condition when procs call MPI_Abort. Since we go thru the errmgr instead of the normal proc termination routines, we need to ensure we mark that the proc has fired its waitpid and is no longer alive. Otherwise, the local daemon won't terminate because it thinks there is still a local proc alive and we hang.

Thanks to Gilles for tracking it down.

cmr=v1.8.2:reviewer=rhc
Small fix for case where no libcuda.so.1 is found.