Support for OpenSSL 1.1.0:

- don't check for SSLeay_version() in configure
  The function no longer exists in 1.1.0.
  It was replaced by OpenSSL_version().
- Switch between SSLeay_version(U) and
  OpenSSL_version() depending on version
  in modules/ssl/ssl_util_ssl.h.
- Use MODSSL_LIBRARY_DYNTEXT everywhere.

Backport of r1728981 from trunk.


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/2.4.x-openssl-1.1.0-compat@1755817 13f79535-47bb-0310-9956-ffa450edef68