workaround for xmlhttp permission denied in viewfeed footer (closes #73)

backend.php

@@ -1248,7 +1248,14 @@
 			<script type=\"text/javascript\">
 				try {
 					document.onkeydown = hotkey_handler;
+					try {
 						parent.update_all_counters(\"$feed\");
+					} catch (e) {
+						// this is workaround against mysterious permission
+						// denied feature/bug of firefox (ticket #73)
+						// if call from this context failed - ignore silently
+						exception_error(\"viewfeed/footer1/counters\", e, true);
+					}
 				} catch (e) {
 					exception_error(\"viewfeed/footer1\", e);
 				}

functions.js

@@ -7,7 +7,7 @@ function browser_has_opacity() {
 		navigator.userAgent.match("Opera") != null;
 }
 
-function exception_error(location, e) {
+function exception_error(location, e, silent) {
 	var msg;
 
 	if (e.fileName) {
@@ -23,8 +23,10 @@ function exception_error(location, e) {
 
 	debug("<b>EXCEPTION: " + msg + "</b>");
 
+	if (!silent) {
 		alert(msg);
 	}
+}
 
 function disableHotkeys() {
 	hotkeys_enabled = false;