Support for SSL Proxies

*Title: Support for SSL Proxies

*Documentation:
Sometimes it is more pratical to just deliver SSL request through a generic proxy. 
This can be the case for development issues or wildcard mass hosting.
For determing the usage of a SSL proxy we evaluate a server variable "HTTP_X_FORWARDED_SERVER" set by webserver.
The value of "HTTP_X_FORWARDED_SERVER" is the value of "ServerName" of the origin virtual host.
The setting is controlled by [SiteSettings].SSLProxyServerName with default value "localhost".

Examples:

Generic SSL Proxy for Apache

LoadModule ssl_module modules/mod_ssl.so 
<IfModule mod_ssl.c>
Listen 443
NameVirtualHost *:443
<VirtualHost *:443>

        ServerAdmin webmaster@localhost
        ServerName localhost

        DocumentRoot /workspace

        SSLEngine on
        SSLCertificateFile C:\workspace\conf\ssl\certs\ca.cer
        SSLCertificateKeyFile C:\workspace\conf\ssl\keys\ca.key

        # security
        SSLProtocol -ALL +SSLv3 +TLSv1
        SSLCipherSuite ALL:!aNULL:!ADH:!eNULL:!LOW:!EXP:RC4+RSA:+HIGH:+MEDIUM

        SetEnvIf User-Agent ".*MSIE.*" \
        nokeepalive ssl-unclean-shutdown downgrade-1.0 force-response-1.0

        RewriteEngine on
        RewriteRule ^/(.*) http://%{HTTP_HOST}/$1 [P,L]
</VirtualHost>
</IfModule>