Disable WordPress 4.7 & 4.7.1 custom CSS

[bobbingwide]

WordPress 4.7 introduced some new code that allows custom CSS to be entered in the customizer.
The custom CSS is saved as a custom post type which WordPress tries to load in the filter hook wp_custom_css_cb.

We don't need this for two reasons

1. We have our own custom CSS code
2. It's a performance overhead. Measured at approx 2% increase in server elapsed time.

Proposed solution

Remove the action hook.
remove_action( 'wp_head', 'wp_custom_css_cb', 11 );

[bobbingwide]

Looks like the hook priority has changed in 4.7.1, so we'll need:
remove_action( 'wp_head', 'wp_custom_css_cb', 101 )