Added wasPressed function to KeyboardInput class

package.json

@@ -1,6 +1,6 @@
 {
   "name": "momentumengine",
-  "version": "0.4.0",
+  "version": "0.5.0",
   "description": "An ES6 game and animation engine.",
   "main": "src/es6.js",
   "repository": {

src/classes/imageloader.js

@@ -15,7 +15,7 @@ class ImageLoader {
             this._error = false;
         });
 
-        this._imageObj.addEventListener("_error", (err) => {
+        this._imageObj.addEventListener("error", (err) => {
             this._loaded = false;
             this._error = err;
         });

src/classes/keyboardinput.js

@@ -99,6 +99,9 @@ const KeyConsts = {
 };
 
 
+let wasReleased = {};
+
+
 class KeyboardInput {
 
 
@@ -119,16 +122,35 @@ class KeyboardInput {
 
 
     isPressed (keyCode) {
+        console.log("[MomentumEngine] WARNING: MomentumEngine.Classes.KeyboardInput.isPressed is deprecated. Use isDown instead.")
         return !!this._keyState[keyCode];
     }
 
+    isDown (keyCode) {
+
+        return !!this._keyState[keyCode];
+    }
+
+    wasPressed (keyCode) {
+
+        let pressed = !!wasReleased[keyCode];
+
+        if (pressed) {
+            wasReleased[keyCode] = false;
+        }
+
+        return pressed;
+    }
+
 
     _keyDownHandler (event) {
+        wasReleased[event.keyCode] = false;
         this._keyState[event.keyCode] = true;
     }
 
 
     _keyUpHandler (event) {
+        wasReleased[event.keyCode = true];
         this._keyState[event.keyCode] = false;
     }