Credits API: Remove `remove_accents()`

[ocean90]

It's time to show people's real name. Follow-up to #117.

I'm going to use the same approach as we're using for the plugins API.

private function _encode( $raw ) {
	$raw = mb_convert_encoding( $raw, 'UTF-8', 'ASCII, JIS, UTF-8, Windows-1252, ISO-8859-1' );
	return ent2ncr( htmlspecialchars_decode( htmlentities( $raw, ENT_NOQUOTES, 'UTF-8' ), ENT_NOQUOTES ) );
}

Let's see how this will work.

[ocean90]

In 2202:

Credits API: Don't remove accents from display names, encode them instead.

Fixes #1478.