Introduce text editor toolbar (#2315)

Tada!

core/modules/macros/displayshortcuts.js

@@ -0,0 +1,45 @@
+/*\
+title: $:/core/modules/macros/displayshortcuts.js
+type: application/javascript
+module-type: macro
+
+Macro to display a list of keyboard shortcuts in human readable form. Notably, it resolves named shortcuts like `((bold))` to the underlying keystrokes.
+
+\*/
+(function(){
+
+/*jslint node: true, browser: true */
+/*global $tw: false */
+"use strict";
+
+/*
+Information about this macro
+*/
+
+exports.name = "displayshortcuts";
+
+exports.params = [
+	{name: "shortcuts"},
+	{name: "prefix"},
+	{name: "separator"},
+	{name: "suffix"}
+];
+
+/*
+Run the macro
+*/
+exports.run = function(shortcuts,prefix,separator,suffix) {
+	var shortcutArray = $tw.keyboardManager.getPrintableShortcuts($tw.keyboardManager.parseKeyDescriptors(shortcuts,{
+		wiki: this.wiki
+	}));
+	if(shortcutArray.length > 0) {
+		shortcutArray.sort(function(a,b) {
+		    return a.toLowerCase().localeCompare(b.toLowerCase());
+		})
+		return prefix + shortcutArray.join(separator) + suffix;
+	} else {
+		return "";
+	}
+};
+
+})();