Append the .PID to the ScriptSock filename. This change ensures that multiple

Append the .PID to the ScriptSock filename. This change ensures that multiple
running instances of httpd will not clobber each others script sockets.

Because a different socket will be created for each instance, this change also
unlinks the script-socket on exit, to prevent pollution.

unlink() happens from within the parent process, since the change in userid's
means the cgid process likely won't have the correct permissions.

git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@240044 13f79535-47bb-0310-9956-ffa450edef68