windows: Add testnet icon for testnet link

Overhauled testnet icon by Jonas Schnelli

share/setup.nsi.in

@@ -92,7 +92,7 @@ Section -post SEC0001
     !insertmacro MUI_STARTMENU_WRITE_BEGIN Application
     CreateDirectory $SMPROGRAMS\$StartMenuGroup
     CreateShortcut "$SMPROGRAMS\$StartMenuGroup\$(^Name).lnk" $INSTDIR\@BITCOIN_GUI_NAME@@EXEEXT@
-    CreateShortcut "$SMPROGRAMS\$StartMenuGroup\@PACKAGE_NAME@ (testnet, @WINDOWS_BITS@-bit).lnk" "$INSTDIR\@BITCOIN_GUI_NAME@@EXEEXT@" "-testnet"
+    CreateShortcut "$SMPROGRAMS\$StartMenuGroup\@PACKAGE_NAME@ (testnet, @WINDOWS_BITS@-bit).lnk" "$INSTDIR\@BITCOIN_GUI_NAME@@EXEEXT@" "-testnet" "$INSTDIR\@BITCOIN_GUI_NAME@@EXEEXT@" 1
     CreateShortcut "$SMPROGRAMS\$StartMenuGroup\Uninstall $(^Name).lnk" $INSTDIR\uninstall.exe
     !insertmacro MUI_STARTMENU_WRITE_END
     WriteRegStr HKCU "SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\$(^Name)" DisplayName "$(^Name)"

src/Makefile.qt.include

@@ -231,6 +231,7 @@ RES_ICONS = \
   qt/res/icons/about.png \
   qt/res/icons/about_qt.png \
   qt/res/icons/bitcoin.ico \
+  qt/res/icons/bitcoin_testnet.ico \
   qt/res/icons/bitcoin.png \
   qt/res/icons/chevron.png \
   qt/res/icons/clock1.png \

src/qt/res/bitcoin-qt-res.rc

@@ -1,4 +1,5 @@
 IDI_ICON1 ICON DISCARDABLE "icons/bitcoin.ico"
+IDI_ICON2 ICON DISCARDABLE "icons/bitcoin_testnet.ico"
 
 #include <windows.h>             // needed for VERSIONINFO
 #include "../../clientversion.h" // holds the needed client version information