Added alt-values to the control-bar buttons.

* On slow servers where the button-images can be slowly loaded it can be useful to see some relevant text instead of "Submit query" on every button.

vnc.html

@@ -49,39 +49,34 @@
     <div id="noVNC-control-bar">
         <!--noVNC Mobile Device only Buttons-->
         <div class="noVNC-buttons-left">
-            <input type="image" src="images/drag.png"
+            <input type="image" alt="viewport drag" src="images/drag.png"
                 id="noVNC_view_drag_button" class="noVNC_status_button"
                 title="Move/Drag Viewport">
             <div id="noVNC_mobile_buttons">
-                <input type="image" src="images/mouse_none.png"
+                <input type="image" alt="No mousebutton" src="images/mouse_none.png"
                     id="noVNC_mouse_button0" class="noVNC_status_button">
-                <input type="image" src="images/mouse_left.png"
+                <input type="image" alt="Left mousebutton" src="images/mouse_left.png"
                     id="noVNC_mouse_button1" class="noVNC_status_button">
-                <input type="image" src="images/mouse_middle.png"
+                <input type="image" alt="Middle mousebutton" src="images/mouse_middle.png"
                     id="noVNC_mouse_button2" class="noVNC_status_button">
-                <input type="image" src="images/mouse_right.png"
+                <input type="image" alt="Right mousebutton" src="images/mouse_right.png"
                     id="noVNC_mouse_button4" class="noVNC_status_button">
-                <input type="image" src="images/keyboard.png"
+                <input type="image" alt="Keyboard" src="images/keyboard.png"
                     id="showKeyboard" class="noVNC_status_button"
                     value="Keyboard" title="Show Keyboard"/>
                 <input type="text" autocapitalize="off" autocorrect="off"
                     id="keyboardinput" class=""/>
                 <div id="noVNC_extra_keys">
-                    <input type="image" src="images/showextrakeys.png"
-                        id="showExtraKeysButton"
-                        class="noVNC_status_button">
-                    <input type="image" src="images/ctrl.png"
-                        id="toggleCtrlButton"
-                        class="noVNC_status_button">
-                    <input type="image" src="images/alt.png"
-                        id="toggleAltButton"
-                        class="noVNC_status_button">
-                    <input type="image" src="images/tab.png"
-                        id="sendTabButton"
-                        class="noVNC_status_button">
-                    <input type="image" src="images/esc.png"
-                        id="sendEscButton"
-                        class="noVNC_status_button">
+                    <input type="image" alt="Extra keys" src="images/showextrakeys.png"
+                        id="showExtraKeysButton" class="noVNC_status_button">
+                    <input type="image" alt="Ctrl" src="images/ctrl.png"
+                        id="toggleCtrlButton" class="noVNC_status_button">
+                    <input type="image" alt="Alt" src="images/alt.png"
+                        id="toggleAltButton" class="noVNC_status_button">
+                    <input type="image" alt="Tab" src="images/tab.png"
+                        id="sendTabButton" class="noVNC_status_button">
+                    <input type="image" alt="Esc" src="images/esc.png"
+                        id="sendEscButton" class="noVNC_status_button">
                 </div>
             </div>
         </div>
@@ -90,22 +85,22 @@
 
         <!--noVNC Buttons-->
         <div class="noVNC-buttons-right">
-            <input type="image" src="images/ctrlaltdel.png"
-                 id="sendCtrlAltDelButton" class="noVNC_status_button"
+            <input type="image" alt="Ctrl+Alt+Del" src="images/ctrlaltdel.png"
+                id="sendCtrlAltDelButton" class="noVNC_status_button"
                 title="Send Ctrl-Alt-Del" />
-            <input type="image" src="images/power.png"
+            <input type="image" alt="Shutdown/Reboot" src="images/power.png"
                 id="xvpButton" class="noVNC_status_button"
                 title="Shutdown/Reboot..." />
-            <input type="image" src="images/clipboard.png"
+            <input type="image" alt="Clipboard" src="images/clipboard.png"
                 id="clipboardButton" class="noVNC_status_button"
                 title="Clipboard" />
-            <input type="image" src="images/settings.png"
+            <input type="image" alt="Settings" src="images/settings.png"
                 id="settingsButton" class="noVNC_status_button"
                 title="Settings" />
-            <input type="image" src="images/connect.png"
+            <input type="image" alt="Connect" src="images/connect.png"
                 id="connectButton" class="noVNC_status_button"
                 title="Connect" />
-            <input type="image" src="images/disconnect.png"
+            <input type="image" alt="Disconnect" src="images/disconnect.png"
                 id="disconnectButton" class="noVNC_status_button"
                 title="Disconnect" />
         </div>