Bad Pango markup crashes the console/HUD

[camgunz]

If you somehow get bad Pango markup in the console or a HUD interface, that interface will stop rendering because Pango refuses to render text with bad markup.

The messaging pipelines are pretty complicated and may need a refactor. But the interim fix is to check new text to see if it contains bad markup and give an error if so. Just dumping whatever into a Pango-processed buffer is bad practice I think.