Remove support for the threaded-mpm's on Linux 2.0, and de-autoconf the

graceful restart signal. Frees up SIGWINCH for implementing graceful stop.
See <20050727114058.GA3390@stdlib.net> and subsequent thread on httpd-dev.



git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@239430 13f79535-47bb-0310-9956-ffa450edef68