Add a thunderbird.exe.manifest file which enable a winxp file picker for win xp builds.

Thanks to Stephen Walker for the patch.

mail/app/splash.rc

@@ -38,6 +38,8 @@
 #include <windows.h>
 #include "nsINativeAppSupportWin.h"
 
+1 24 "thunderbird.exe.manifest" 
+
 // Splash screen dialog ID.
 #define IDD_SPLASH  100
  

mail/app/thunderbird.exe.manifest

@@ -0,0 +1,22 @@
+<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
+<assembly xmlns="urn:schemas-microsoft-com:asm.v1" manifestVersion="1.0">
+<assemblyIdentity
+        version="1.0.0.0"
+        processorArchitecture="X86"
+        name="Microsoft.Winweb.MantaRay"
+        type="win32"
+/>
+<description>.NET control deployment tool</description>
+<dependency>
+        <dependentAssembly>
+                <assemblyIdentity
+                        type="win32"
+                        name="Microsoft.Windows.Common-Controls"
+                        version="6.0.0.0"
+                        processorArchitecture="X86"
+                        publicKeyToken="6595b64144ccf1df"
+                        language="*"
+                />
+        </dependentAssembly>
+</dependency>
+</assembly>