Install script refactor

Refactored install script to be a bit more styleable (install steps are now in a definition list); ported relevant styles to LESS for ease of editing; edited require of config.php to require_once based on the location of php/func.php; amended define() calls to reduce php erroring; cleaned up some whitespace and trailing spaces.

Install script now looks like this: http://puu.sh/8K8ss/64cef2aa2a.png