Log a warning if ThreadStackSize has an inappropriate value.

PR : 54311
Submitted by: Tianyin Xu <tixu cs ucsd edu>

Only event.c has been compiled on my system. The 2 others are just cut and paste.
I have left the same value for APLOGNO in event and eventopt has for the other logged messages. I don't know if it is the right way to do.

git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@1433682 13f79535-47bb-0310-9956-ffa450edef68