NSIS: Add custom VLC banner image

This adds a custom VLC banner image to the welcome and finish page of
the NSIS installer and uninstaller.

Note: If there is ever need to re-generate the bmp banner image,
use a custom color pallet, this allows to only need 4 bits per color and
drastically reduces the size. Do not write colorspace information.
Use Run-length coding.

extras/package/win32/NSIS/vlc.win32.nsi.in

@@ -79,6 +79,11 @@ RequestExecutionLevel admin
   !define MUI_UNICON "vlc.ico"
   !define MUI_COMPONENTSPAGE_SMALLDESC
 
+  ; Banner (welcome and finish page) for installer
+  !define MUI_WELCOMEFINISHPAGE_BITMAP "NSIS/vlc_branding.bmp"
+  ; Banner for uninstaller
+  !define MUI_UNWELCOMEFINISHPAGE_BITMAP "NSIS/vlc_branding.bmp"
+
 ; Installer pages
   ; Welcome page
     !define MUI_PAGE_CUSTOMFUNCTION_PRE PageFastUpdatePre