Move release.h to ap_release.h. This was done to namespace protect the

release header file.  While doing this, I also made sure that the file
was only included once.
Submitted by:	Greg Stein


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@87977 13f79535-47bb-0310-9956-ffa450edef68