Updates Apache.conf to 2.4 defaults, adressing https://github.com/Mins/TuxLite/issues/46

I wanted to use TuxLite to provision a fresh install of Ubuntu 14.04 LTS but found that, as described in https://github.com/Mins/TuxLite/issues/46, installation fails with errors from Apache.

I went through the Apache 2.2> 2.4 upgrade checklist at: http://httpd.apache.org/docs/2.4/upgrading.html and updated the default conf accordingly.

After these changes the script was run in a clean install of Ubuntu 14.04 LTS and completed successfully. 

Please note, I have *not* tested these changes against any other distro.