Better Theme Integration

[mnelson4]

I realized I might be able to have themes active while also disabling their CSS.
On setup_theme action, record the styles (and scripts?) enqueued, and which new callbacks were set on init and enqueue_scripts; on after_setup_theme remove them.

This way, we could default to having the theme active, without using its CSS.

Helpful: https://codex.wordpress.org/Plugin_API/Action_Reference