add fade-in to shortcut help overlay

prefs.js

@@ -1754,7 +1754,8 @@ function pref_hotkey_handler(e) {
 	
 			if (keycode == 191 && shift_key) { // ?
 				if (!Element.visible("hotkey_help_overlay")) {
-					Element.show("hotkey_help_overlay");
+					//Element.show("hotkey_help_overlay");
+					Effect.Appear("hotkey_help_overlay", {duration : 0.3});
 				} else {
 					Element.hide("hotkey_help_overlay");
 				}

prefs.php

@@ -110,7 +110,7 @@ window.onload = init;
 		</div> -->
 
 		<div class='prefKbdHelp'>
-			<img src="images/small_question.png" alt="?"> <a href='#' onclick="Element.show('hotkey_help_overlay')">Keyboard shortcuts</a>
+			<img src="images/small_question.png" alt="?"> <a href='#' onclick="Effect.Appear('hotkey_help_overlay', {duration: 0.3})">Keyboard shortcuts</a>
 		</div>
 
 		<div class="firstTab">&nbsp;</div>

tt-rss.js

@@ -530,7 +530,8 @@ function quickMenuGo(opid) {
 		}
 
 		if (opid == "qmcHKhelp") {
-			Element.show("hotkey_help_overlay");
+			//Element.show("hotkey_help_overlay");
+			Effect.Appear("hotkey_help_overlay", {duration : 0.3});
 		}
 
 	} catch (e) {
@@ -973,7 +974,8 @@ function hotkey_handler(e) {
 	
 			if (keycode == 191 && shift_key) { // ?
 				if (!Element.visible("hotkey_help_overlay")) {
-					Element.show("hotkey_help_overlay");
+					//Element.show("hotkey_help_overlay");
+					Effect.Appear("hotkey_help_overlay", {duration : 0.3});
 				} else {
 					Element.hide("hotkey_help_overlay");
 				}