commit b3377c5

Render the Unicode replacement character properly

Previously, we stopped rendering a line on its first Unicode replacement
character, because we used that special value for detecting invalid
Unicode bytes.

Now that we pre-process incoming strings to replace invalid Unicode
bytes with the Unicode replacement character [1], there is no need to
stop rendering a string on this character: it should just be passed
through as is.

[1]: 700139404044730a726af7cd57e3d2dbc07871ea

 1@@ -274,9 +274,6 @@ func IRCString(raw string) StyledString {
 2 
 3 	for len(raw) != 0 {
 4 		r, runeSize := utf8.DecodeRuneInString(raw)
 5-		if r == utf8.RuneError {
 6-			break
 7-		}
 8 		_, _, lastAttrs := last.Decompose()
 9 		current := last
10 		if r == 0x0F {