*_option() should all expect unslashed data.

[Denis-de-Bernardy]

Following up on:

http://core.trac.wordpress.org/ticket/9015#comment:136

It's totally irresponsible to expect plugin authors to escape whatever they send into get_option(). As things stand:

• get_option(), delete_option(), get_site_option() both assume it's slashed
• add_option(), update_option(), add_site_option() seem to assume it's unslashed, as does get_option()
• *_transient() seem to expect unslashed input.
• delete_site_option() is very special: it expects slashed input if you're not on using multisite, but unslashed if you are
• update_site_option() is equallty special: it needs slashed input if the option is not loaded already, and unslashed input if it is

the list goes on, and on... these inconsistencies, which come on top of the *_meta() functions, are totally nuts and insecure.

especially considering calls in WP such as:

• get_option("{$size}_crop");

or functions such as:

function form_option( $option ) {
	echo esc_attr( get_option( $option ) );
}

function get_settings_errors( $setting = '', $sanitize = FALSE ) {
	global $wp_settings_errors;
	//... isn't it ironic that using sanitize here makes it LESS secure?
	if ( $sanitize )
		sanitize_option( $setting, get_option($setting));
	// ...