[MAIL] Remove What's new menu item and code that pops up What's new on upgrade which won't trigger anyway because of how versions are done for Interlink

mail/base/content/baseMenuOverlay.xul

@@ -40,9 +40,6 @@
                 oncommand="openSupportURL();"
                 key="key_openHelp"/>
 #endif
-      <menuitem id="whatsNew"
-                label="&whatsNewCmd.label;" accesskey="&whatsNewCmd.accesskey;"
-                oncommand="openWhatsNew();"/>
       <menuitem id="releaseNotes"
                 label="&releaseCmd2.label;" accesskey="&releaseCmd2.accesskey;"
                 oncommand="openFormattedURL('app.releaseNotesURL');"/>

mail/base/content/mailWindowOverlay.xul

@@ -2095,9 +2095,6 @@
                         label="&openHelp.label;"
                         key="key_openHelp"
                         oncommand="openSupportURL();"/>
-              <menuitem id="appmenu_whatsNew"
-                        label="&whatsNewCmd.label;"
-                        oncommand="openWhatsNew();"/>
               <menuitem id="appmenu_releaseNotes"
                         label="&releaseCmd2.label;"
                         oncommand="openFormattedURL('app.releaseNotesURL');"/>

mail/base/content/specialTabs.js

@@ -596,14 +596,6 @@ var specialTabs = {
     // check this pref anyway and clear it so that we are consistent with what Firefox
     // actually does. It will help developers switching between branches without updating.
     if (Services.prefs.prefHasUserValue("app.update.postupdate")) {
-      // Only show what's new tab if this is actually an upgraded version,
-      // not just a new installation/profile (and don't show if the major version
-      // hasn't changed).
-      if (fromVer && (fromVer[0] != toVer[0])) {
-          // showWhatsNewPage checks the details of the update manager before
-          // showing the page.
-          this.showWhatsNewPage();
-      }
       Services.prefs.clearUserPref("app.update.postupdate");
     }
 

mail/locales/en-US/chrome/messenger/baseMenuOverlay.dtd

@@ -15,8 +15,6 @@
 <!ENTITY helpSafeMode.accesskey "R">
 <!ENTITY releaseCmd2.label "Release Notes">
 <!ENTITY releaseCmd2.accesskey "N">
-<!ENTITY whatsNewCmd.label "What's New">
-<!ENTITY whatsNewCmd.accesskey "W">
 <!ENTITY openHelp.label "Help Contents">
 <!ENTITY openHelp.accesskey "H">
 <!ENTITY openHelp.commandkey "VK_F1">