Finished implementing pixel grid

Added possibility to hide / show the grid.

views/pixel-editor.hbs

@@ -58,6 +58,12 @@
                 <li><button id="redo-button" class="disabled">Redo</button></li>
             </ul>
         </li>
+        <li>
+            <button>View</button>
+            <ul>
+                <li><button id="toggle-pixelgrid-button" onclick="togglePixelGrid()">Show pixel grid</button></li>
+            </ul>
+        </li>
         <li>
             <button id = "layer-button">Layer</button>
             <ul>