* Introduce MCI cache: Art files are hashed and MCI info (per client) is cached. Term resizes invalidate the cache

* Bring in farmhash for art file hashing (and perhaps other uses soon)
* Re-write of art.js display(). Better system, use MCI cache, etc.
* Update package.json engines node req.

core/client.js

@@ -82,6 +82,11 @@ function Client(input, output) {
 	this.lastKeyPressMs		= Date.now();
 	this.menuStack			= new MenuStack(this);
 	this.acs				= new ACS(this);
+	this.mciCache			= {};
+
+	this.clearMciCache = function() {
+		this.mciCache = {};
+	};
 
 	Object.defineProperty(this, 'node', {
 		get : function() {