Move public APIs into their own folder

And start writing actual tests for them

api/limiter.js

@@ -0,0 +1,35 @@
+var FRAME_BUDGET = 16 // 60 frames per second = 1 call per 16 ms
+
+module.exports = function($window, render) {
+	var rAF = $window.requestAnimationFrame || $window.setTimeout
+	var cAF = $window.cancelAnimationFrame || $window.clearTimeout
+	
+	var last = 0
+	var pending
+	
+	return function() {
+		var now = new Date()
+		
+		// First render, OR if the time since the last render is greater
+		// than the frame budget
+		// just immediately render
+		if(!last || now - last > FRAME_BUDGET) {
+			last = now;
+			
+			return render()
+		}
+		
+		// Redraw already pending, abort
+		if(pending) {
+			return
+		}
+		
+		// Schedule a redraw for the next tick
+		pending = rAF(function() {
+			render()
+			
+			last = new Date()
+			pending = null
+		}, FRAME_BUDGET - (now - last))
+	}
+}