Windows installer

[Germán Arias]

For those interested, here are available a GNUstep installer for
Windows:

https://www.dropbox.com/s/mb4m65spkuf3o0f/GNUstep-1.0.exe?dl=0

Aside of the basic packages (make, base, gui and back) this installer
includes the framework Renaissance. Also the apps SystemPreferences,
Gorm and Gemas. And Emacs 24.4.

By default the cairo backend and the theme WinUXTheme are used.

There are only two changes with the development code in the repository:

* For the cairo backend only buffered windows are used. So the "drag &
  drop" shown images, not black rectangles.

* In the WinUXTheme -doesProcessEventsForPopUpMenu returns NO. This is
  which work for me.

This has been tested on Windows 7, 32 and 64 bits. So Happy Hacking!

Germán