Added some comments that will help us make this more portable.
tmpnam() is not portable to platforms that will not inhereit
the process, so we need to pull the lock filename from somewhere
shared, like a configuration directive.


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@93533 13f79535-47bb-0310-9956-ffa450edef68