[PR] General Cleanup

* Adds a stylesheet so that the theme can be activated
* Removes references to `spine.dev`, uses parent theme styles. (This may need to change if this is a parent theme)
* Cleans up code a bit

@natejacobson - There are a couple undefined functions in `format-single.php` that should be defined or removed before we push this to production. I may do another sweep for unescaped/sanitized data.