Move input handling into Level and clean it up a ton; add a bulk test gizmo

index.html

@@ -55,9 +55,10 @@
     <header id="header-pack">
         <h2 id="level-pack-name">Chip's Challenge Level Pack 1</h2>
         <nav>
+            <button id="main-test-pack" type="button">Bulk test</button>
             <button id="main-change-pack" type="button">Change pack</button>
             <button id="player-edit" type="button">Edit</button>
-            <button id="editor-play" type="button">Test</button>
+            <button id="editor-play" type="button">Play</button>
         </nav>
     </header>
     <header id="header-level">