* Scan /var/log/openafs for core files with a PID appended when a server

* Scan /var/log/openafs for core files with a PID appended when a server
  run by bosserver exits with a signal.  bosserver was unable to
  correctly handle core files for multithreaded servers since it
  expected a filename of core and Linux always appends a PID to core
  dumps by multithreaded processes.
* Stop creating /var/lib/openafs/cores.  Nothing actually uses it.