Add more options to the ap_mpm_query function. This also allows MPMs to

Add more options to the ap_mpm_query function.  This also allows MPMs to
report if their threads are dynamic or static.  Finally, this also
implements a new API, ap_show_mpm, which returns the MPM that was
required into the core.

We tried to make all of the MPMs report their threading capabilities
correctly, but each MPM expert should double check us.

Submitted by:	Harrie Hazewinkel <harrie@covalent.net>

git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@88851 13f79535-47bb-0310-9956-ffa450edef68