Initial version of hot-reload of config, menus, and prompts

* Themes use ES6 Map vs object{}
* Re-write and re-enable config cache using sane
* Events sent for config, prompt, or menu changes
* Event sent for theme changes
* Theme (or parent menu/prompt) changes cause re-merge and updates to connected clients

core/client.js

@@ -38,6 +38,7 @@ const User		= require('./user.js');
 const Config	= require('./config.js').config;
 const MenuStack	= require('./menu_stack.js');
 const ACS		= require('./acs.js');
+const Events	= require('./events.js');
 
 //	deps
 const stream	= require('stream');
@@ -110,6 +111,12 @@ function Client(/*input, output*/) {
 		this.input.on('data', this.dataHandler);
 	};
 
+	Events.on(Events.getSystemEvents().ThemeChanged, ( { themeId } ) => {
+		if(_.get(this.currentTheme, 'info.themeId') === themeId) {
+			this.currentTheme = require('./theme.js').getAvailableThemes().get(themeId);
+		}
+	});
+
 
 	//
 	//	Peek at incoming |data| and emit events for any special