A critical pango fix

I've just pushed a fix to pango:

This prevents and assertion which can be triggered by invalid Unicode sequences.

I'll be doing a release with this fix shortly, but since this can crash apps like hexchat

or gnome-terminal, it is a good idea to get the patch out as soon as possible.

This affects all versions of Pango since color Emoji support was introduced in 1.40.8.

Matthias