Avoid using the Include directive.  Move most of the SSL configuration
to the global configuration and leave enabling the SSL engine to each
virtual host that wants to use it.

See https://wiki.mozilla.org/Security/Server_Side_TLS for details.
Removes RC4 cipher. Fixes issue #341.
Also explicitly disabled SSLCompression and enables OCSP stapling.

We should put all these settings in
/etc/apache2/mods-enabled/ssl.conf
to avoid duplication...