Add AP_MPMQ_MPM_STATE function code for ap_mpm_query.

(not currently supported for Win32, BeOS, or OS/2 MPMs)

Submitted by:	Jeff Trawick, Brad Nicholes
Reviewed by:	stoddard, jerenkrantz


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/APACHE_2_0_BRANCH@102125 13f79535-47bb-0310-9956-ffa450edef68