Rename Present button to Panic.

static/sfu.html

@@ -39,12 +39,12 @@
               <ul class="nav-menu">
                 <li>
                   <button id="presentbutton" class="invisible btn btn-success">
-                    <i class="fas fa-video" aria-hidden="true"></i><span class="nav-text"> Present</span>
+                    <i class="fas fa-play" aria-hidden="true"></i><span class="nav-text"> Ready</span>
                   </button>
                 </li>
                 <li>
                   <button id="unpresentbutton" class="invisible btn btn-cancel">
-                    <i class="fas fa-stop" aria-hidden="true"></i><span class="nav-text"> Stop presenting</span>
+                    <i class="fas fa-stop" aria-hidden="true"></i><span class="nav-text"> Panic</span>
                   </button>
                 </li>
                 <li>