update to use svg for buttons

Author: greggman

Assets/WebPlayerTemplates/HappyFunTimes/controller.html

@@ -1,9 +1,9 @@
     <!-- this is inserted into index.html by build.py -->
     <div id="buttons" class="hft-fullsize">
-      <div class="button" id="left">◀</div>
-      <div class="button" id="right">▶</div>
+      <div class="button" id="left"><img src="images/hft-left-arrow-button.svg" /></div>
+      <div class="button" id="right"><img src="images/hft-right-arrow-button.svg" /></div>
       <canvas id="avatar"></canvas>
-      <div class="button" id="up">▲</div>
+      <div class="button" id="up"><img src="images/hft-up-arrow-button.svg" /></div>
     </div>
     <div id="hft-portrait" class="hft-fullsize hft-fullcenter">
       <div class="hft-portrait-rot90">

Assets/WebPlayerTemplates/HappyFunTimes/css/controller.css

@@ -40,10 +40,6 @@ html, body {
     user-select: none;
 }
 .button {
-    background-color: #fff;
-    color: #000;
-    border: 3px solid #444;
-    border-radius: 10px;
     width: 110px;
     height: 110px;
     text-align: center;