New releases of OpenSSL will only allow secure renegotiation by

New releases of OpenSSL will only allow secure renegotiation by
default.  Add an "SSLInsecureRenegotiation" directive to enable
renegotiation against unpatched clients, to ease transition:

* modules/ssl/ssl_private.h (struct SSLSrvConfigRec): Add
  insecure_reneg field.

* modules/ssl/ssl_engine_config.c (ssl_config_server_new,
  ssl_config_server_merge): Handle the insecure_reneg flag.
  (ssl_cmd_SSLInsecureRenegotiation): New function.

* modules/ssl/ssl_engine_init.c (ssl_init_ctx_protocol): Set the
  SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION option if insecure_reneg is
  enabled.

* modules/ssl/ssl_engine_kernel.c (ssl_hook_Access): Log level of
  support for secure reneg.

* modules/ssl/mod_ssl.c: Add the directive definition.

git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@906039 13f79535-47bb-0310-9956-ffa450edef68