Checks and cleans a URL.

A number of characters are removed from the URL. If the URL is for displaying
(the default behavior) ampersands are also replaced. The ‘clean_url’ filter
is applied to the returned cleaned URL.

function clean_url( $url, $protocols = null, $context = 'display' ) {
	if ( $context == 'db' )
		_deprecated_function( 'clean_url( $context = 'db' )', '3.0.0', 'sanitize_url()' );
	else
		_deprecated_function( __FUNCTION__, '3.0.0', 'esc_url()' );
	return esc_url( $url, $protocols, $context );
}