Convert the "Input Source List Changed notification" too.
Remap all hotkeys at once when the keyboard layout changes.
Use `instancetype` instead of `id`.
Fix conversion from an array of unichars to an NSString.

The former would tack on a few NULLs, and then comparison would fail down from here because we'd have (unexpected) different lengths.
Order the modifiers based on how they appear in menus.
Try ASCII-compatible layouts first, so that non-latin keyboards don't fail.