Support unicode input

[vgmoose]

Right now things get kinda weird when rendering unicode characters. Saving the file seems ok, but editing it is flakey, and you can do weird things like delete half of a character.

For instance, take the following text file:

🐕

This appears in vgedit as 5 blank spaces and a newline. Editing everything around it is okay, but you're dealing with an invisible object that you don't want to break up.

To fix this bug, changes in the font rendering library / cursor-positioning character-counting logic may be needed

[vgmoose]

This also applies to Japanese, Chinese, and Korean characters and text, they are rendered as multiple empty spaces.