Added hint to filter button tooltips about the shortcut for selecting

multiple filters (related to issue 4621 and issue 4156)

extension/content/firebug/console/consolePanel.js

@@ -97,6 +97,18 @@ Firebug.ConsolePanel.prototype = Obj.extend(Firebug.ActivablePanel,
         if (!this.persistedContent && Firebug.Console.isAlwaysEnabled())
             this.insertLogLimit(this.context);
 
+        // Initialize filter button tooltips
+        var doc = this.context.chrome.window.document;
+        var filterButtons = doc.getElementsByClassName("fbConsoleFilter");
+        for (var i=0, len=filterButtons.length; i<len; ++i)
+        {
+            if (filterButtons[i].id != "fbConsoleFilter-all")
+            {
+                filterButtons[i].tooltipText = Locale.$STRF("firebug.labelWithShortcut",
+                    [filterButtons[i].tooltipText, Locale.$STR("tooltip.multipleFiltersHint")]);
+            }
+        }
+
         // Listen for set filters, so the panel is properly updated when needed
         Firebug.Console.addListener(this);
     },

extension/content/firebug/net/netPanel.js

@@ -85,6 +85,18 @@ NetPanel.prototype = Obj.extend(Firebug.ActivablePanel,
 
         Firebug.ActivablePanel.initialize.apply(this, arguments);
 
+        // Initialize filter button tooltips
+        var doc = this.context.chrome.window.document;
+        var filterButtons = doc.getElementsByClassName("fbNetFilter");
+        for (var i=0, len=filterButtons.length; i<len; ++i)
+        {
+            if (filterButtons[i].id != "fbNetFilter-all")
+            {
+                filterButtons[i].tooltipText = Locale.$STRF("firebug.labelWithShortcut",
+                    [filterButtons[i].tooltipText, Locale.$STR("tooltip.multipleFiltersHint")]);
+            }
+        }
+
         // Listen for set filters, so the panel is properly updated when needed
         Firebug.NetMonitor.addListener(this);
     },

extension/locale/en-US/firebug.properties

@@ -819,6 +819,12 @@ console.Use_Arrow_keys,_Tab_or_Enter=Use Arrow keys, Tab or Enter
 # LOCALIZATION NOTE (console.JSDisabledInFirefoxPrefs): Hint shown inside the Console panel in the case
 # JavaScript is not available
 console.JSDisabledInFirefoxPrefs=JavaScript is disabled in your Firefox preferences. If you want to use the Console panel, then please enable this option via Tools > Options > Content > Enable JavaScript
+
+# LOCALIZATION NOTE (tooltip.multipleFiltersHint):
+# Hint used for Console and Net panel filter button tooltips describing the shortcut for selecting
+# multiple filters
+tooltip.multipleFiltersHint=Use Ctrl+Click to select multiple filters
+
 # LOCALIZATION NOTE (console.multiHighlightLimitExceeded):
 # Used by the Console panel for arrays. If the user moves the mouse over an array bracket,
 # all elements in the array are highlighted on the page. If there are too many elements