sanitize_option() adds and strip slashes to use the wrong kses functions

[nacin]

sanitize_option() does this:

$value = addslashes($value);
$value = wp_filter_post_kses( $value ); // calls stripslashes then addslashes
$value = stripslashes($value);

When it should instead do this:

$value = wp_kses_post( $value );

Likewise for wp_filter_kses() versus wp_kses_data().

[nacin]

In [21850]:

Use the non-slashing variants of kses functions in sanitize_option() to avoid slash ping pong. fixes #21892.