Changed the SSLCipherSUite list to 'intermediate'

The 'intermediate' cipher suite list is now being used instead of the '
modern' one for greater comaptibility with a wider range of browsers.
Included an ssl.conf.include file for ssl config

Some lines of ssl config have been replaced by a ssl.conf.include file,
which is a much more flexible approach to configuration.
Added the setenvif module

The module was necessary for some configuration in ssl.conf.include.
Merge pull request #33 from ausaccessfed/bugfix/ssl-config

Hardened the ssl configuration