REPL: Add support for elastic tabstops

[ExE-Boss]

Elastic tabstops allow for better code alignment using tabs.

There is already a JavaScript library for this, but I would recommend using my fork, because it has support for JSDoc and fixes some issues with the original implementation.

Example:

A code written like so:

const languageData = {
	en: {
		appTitle:	{ "message":	"Some app"	},
		description:	{ "message":	"This application does things"	},

		options:	{ "message":	"Options"	},
		options_theme:	{ "message":	"Theme:"	},
		options_theme_default:	{ "message":	"Default Theme"	},
		options_theme_colorful:	{ "message":	"Colorful Theme"	}
	},

	en_GB: {
		options_theme_colorful:	{ "message":	"Colourful Theme"	}
	}
}

export const translateMessage = (message) => {
	const navLang	= navigator.language.split("-");
	let translated	= undefined;
	let prevLang	= undefined;

	for (let i = 0; i < navLang.length; i++) {
		let stuff	= navLang[i];
		if (prevLang) {
			stuff	= `${prevLang}_${stuff}`;
		}
		translated = languageData[stuff][message] || translated;
	}
	
	return translated;
}

Would render like so:

const languageData = {
	en: {
		appTitle:    { "message": "Some app"                     },
		description: { "message": "This application does things" },

		options:                { "message": "Options"        },
		options_theme:          { "message": "Theme:"         },
		options_theme_default:  { "message": "Default Theme"  },
		options_theme_colorful: { "message": "Colorful Theme" }
	},

	en_GB: {
		options_theme_colorful: { "message": "Colourful Theme" }
	}
}

export const translateMessage = (message) => {
	const navLang  = navigator.language.split("-");
	let translated = undefined;
	let prevLang   = undefined;

	for (let i = 0; i < navLang.length; i++) {
		let stuff = navLang[i];
		if (prevLang) {
			stuff = `${prevLang}_${stuff}`;
		}
		translated = languageData[stuff][message] || translated;
	}
	
	return translated;
}

(If this gets implemented then space indented code might finally die once and for all, because space indented code is much bigger than tab indented code (4 bytes (4 spaces) vs 1 byte (1 tab)).)