[dev] Need help implementing combining characters

[Random832]

I've got the logic fully implemented (both for maintaining multiple 
characters in a single cell and for copying the selection) but I can't 
figure out how to make them draw correctly. I don't understand what the 
xdraws and drawregion function is doing.

Current behavior is it draws the combining glyph in a cell of its own 
next to the base glyph.