Removed pid_exists() check in get_process_info() since BSD seems to correctly error out sysctl with ESRCH if the process goes away. OS X does not so the check remains on OS X but we can remove from FreeBSD.
Removed pid_exists() check in get_process_info() since BSD seems to correctly
error out sysctl with ESRCH if the process goes away. OS X does not so the
check remains on OS X but we can remove from FreeBSD.

ztop/psutil,ztop/psutil,ztop/psutil,ztop/psutil