Preview window blank on Linux

[alerque]

The panic opening the preview window in #231 does seem to be fixed, the window opens now. The only trouble is it's blank and I can't figure out how to get anything to show in it:

The font I'm testing here only has capital glyphs, but I entered a preview text in all caps and still don't get anything on the canvas.

[cmyr]

It looks like that font doesn't have unicode values set for the glyphs, which means we can't find them when we try to do the shaping.

This is a bit of a pain; you can't currently add the unicode values directly, we do it for you automatically when you set the name of the glyph. I'm not sure how these ones were removed, but i noticed that this file has been normalized at some point, and so maybe it was edited outside of runebender by eli, and that caused the missing unicode values?