Introduce SSLFIPS directive to support OpenSSL FIPS_mode; permits all

builds of mod_ssl to use 'SSLFIPS off' for portability, but the proper
build of openssl is required for 'SSLFIPS on'.  

PR: 46270  
Submitted by: Dr Stephen Henson <steve openssl.org>, wrowe



git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@925980 13f79535-47bb-0310-9956-ffa450edef68