Checkbox for enabling/disabling styles

This fixes #17
Update popup.js
Arrow cursor on style name
Clicking the style name now toggles it as well
Fixed the checkbox

There, now everything should work. It's not ideal though, I need to figure out how to shorten it.
Update compress
Revert "Update compress"

This reverts commit 3835a69770e2980e5bd6f4bb7f2526dce9a3d7e7.
Merge branch 'master' of https://github.com/Baegus/stylish-chrome
Don't show disabled-looking controls for disabled styles, code cleanup #20