TODO
====

2018.09.24:
v Add `MapGroup` to `State` (2018.09.25)
	v FFI function to load `MapGroup` into `State` (2018.09.25)
v Dealloc `_state`
v Key simulation for special keys
	v F1 etc.
	v Modifier keys
	v Escaping
		:help <>
		1.  Any printable characters are typed directly, except backslash and '<'
		2.  A backslash is represented with "\\", double backslash, or "<Bslash>".
		3.  A real '<' is represented with "\<" or "<lt>".  When there is no
			confusion possible, a '<' can be used directly.
	v Figure out special function keys like volume, media, etc.
	v <nop>
	- Default keys
v Fix: when in mode, non-mode mappings should not be enabled
v Command handling
- DKMap Parser
	- Fail if no newline at the end of the file
- Cleanup
	v Remove result from `run_key_action_for_mode()`
	v Remove Objective-C key press simulation
	v C header file
	v cocoa_bridge
		v Rename to `ffi` module
		v Get rid of unused structs
		v Get rid of debug print statements
	- Get rid of `unwrap`s and `expect`s
- Documentation
	- README
	- Code docs
	- man page(s)
/ Command-line argument handling
	x Custom config file
	x DKMap file
	v Register license
	v Daemon
	v Reload DKMap file (XPC services, communicate with running daemon to reload
	  its mappings)
	- Write LaunchAgent plist file
v Config file
	v Read from a config file (XDG etc.)
	v Timeout
	x Log file? (Thinking always stdout)
- LaunchAgent
v Load mappings from file
/ Logging
	/ Always output consistent timestamp
	/ Log errors
	/ Remove `unwrap`s
	- Check error messages of parser
- Other headphones
	v Test with single-button headphones (<prev>/<next>)
		> Only triggers a middle button, no prev or next
	v Test with Bluetooth headphones (--doesn't work)
	- Make it work with Bluetooth headphones
		See:
			. https://stackoverflow.com/questions/32499676/capture-osx-media-control-buttons-in-swift
			. https://github.com/nevyn/SPMediaKeyTap
			. https://weblog.rogueamoeba.com/2007/09/29/
/ Licensing
	v Add Aquatic Prime or some such
	v 30-day trial
	- Check that you can still register after trial expires
/ Audio
	v Mode activated
	v Mode deactivated
	/ Play audio on mode change
- DKMap editor plugins
	- Vim
	- Emacs
- Homebrew formula
- Website
- Demo video