Simplify

Various changes, fixes #21

* Remove `output dir`; favicons should always be in the root of the site and we already know that location via `:build_dir`
* Don't `gsub` filepath in #say_status since it's done by default already, also use `:create` instead of `:generate` in line with middleman defaults
* Don't remove files, use middleman's built-in `app.ignore` method by simply adding an underscore before the template filename
* Refactor away the configuration block and private methods as they're not needed

This is just a fork I have been using for a bit and thought I may as well throw it in a PR, you probably won't agree with all the changes but I wanted to make you aware of these points. =]