Font fallback fails if main font's properties don't match fallback font

[CryZe]

It seems like font fallback generally works pretty well, but if a certain property, such as italics are not available for the fallback font, the font is not chosen at all and tofus are rendered instead.

Here's an example where Calibri is the main font. Calibri by itself does not support Hangul, so it falls back to a different font (seems to be Malgun Gothic). This works fine until you choose Calibri Italic, at which point it can't find an italic version of Malgun Gothic and shows tofus.

This may or may not be related to #58. I'm surprised the fallback is rejected if found in the first place though, so it may not actually be related.