Support non-English keyboard languages

Use event.which if it is lower than the parsed key identifier.
This is the case when a non-English keyboard language is selected and
a physical English keyboard is being used.

This allows keybindings to still work even when the physical key pressed
is different than the key it maps to for the currently selected language.

Closes #585

src/app/keymap.coffee

@@ -150,6 +150,7 @@ class Keymap
     if event.originalEvent.keyIdentifier.indexOf('U+') == 0
       hexCharCode = event.originalEvent.keyIdentifier[2..]
       charCode = parseInt(hexCharCode, 16)
+      charCode = Math.min(event.which, charCode) if event.which?
       key = @keyFromCharCode(charCode)
     else
       key = event.originalEvent.keyIdentifier.toLowerCase()