TODO
====

2018.09.24:
- Add `MapGroup` to `State`
	- FFI function to load `MapGroup` into `State`
- Dealloc `_state`
- Key simulation for special keys
	- F1 etc.
	- Modifier keys
- Fix: when in mode, non-mode mappings should not be enabled
- Command handling
- DKMap Parser
	- Fail if no newline at the end of the file
- Cleanup
	- Remove result from `run_key_action_for_mode()`
	- Remove Objective-C key press simulation
	- C header file
	- cocoa_bridge
		- Rename to `ffi` module
		- Get rid of unused structs
		- Get rid of debug print statements
- Documentation
	- README
	- Code docs
- Command-line argument handling
	- Custom config file
	- DKMap file
	- Register license
	- Daemon
	- Reload DKMap file (XPC services, communicate with running daemon to reload
	  its mappings)
	- Write LaunchAgent plist file
- Config file
	- Read from a config file (XDG etc.)
	- Timeout
	- Log file? (Thinking always stdout)
- LaunchAgent
- Load mappings from file
- Logging
	- Always output consistent timestamp
	- Log errors
	- Remove `unwrap`s
	- Check error messages of parser
- Other headphones
	- Test with single-button headphones (<prev>/<next>)
	- Test with Bluetooth headphones
- Licensing
	- Add Aquatic Prime or some such
	- 30-day trial
- Audio
	- Mode activated
	- Mode deactivated
- DKMap editor plugins
	- Vim
	- Emacs
- Homebrew formula
- Website
- Demo video