mod_ssl: Add hooks to allow other modules to perform processing at

several stages of initialization and connection handling.  See
mod_ssl_openssl.h.

This is enough to allow implementation of Certificate Transparency
outside of mod_ssl.


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@1587607 13f79535-47bb-0310-9956-ffa450edef68