(PATCH) SPI_GETDESKWALLPAPER Implementation

[Philipp Wollermann]

Hello,

this is my first real patch for Wine. It implements the SystemParametersInfo 
SPI_GETDESKWALLPAPER action and fixes SPI_SETDESKWALLPAPER so it updates the 
Wallpaper entry in the registry. (Wine Bug-Tasklet #461)
I've also included a simple test for these two actions. Please tell me if 
something is wrong so I can fix it. :-)

ChangeLog:
* windows/sysparams.c:
Implemented SPI_GETDESKWALLPAPER action, fixed SPI_SETDESKWALLPAPER

* dlls/user/tests/sysparams.c
Added test for wallpaper actions

License: X11 / LGPL

Philipp Wollermann