minor scoreboard/status improvements:

. get the SS field in extended status output formatted correctly
  (seconds since beginning of request shouldn't be a huge
  negative number :) )
. use APR_OS_PID_T_FMT and pid_t where appropriate in mod_status
  to avoid casting, some of which may have been broken on some
  architectures


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@89048 13f79535-47bb-0310-9956-ffa450edef68