Update the registry keys of SPI_ICONHORIZONTALSPACING,

Update the registry keys of SPI_ICONHORIZONTALSPACING,
SPI_ICONVERTICALSPACING and SPI_SETICONTITLEWRAP to match XP.
The SPI_SETBORDER test leaves an incorect border setting and is just
too erratic: comment it out for now.
Modified the SPI_ICONHORIZONTALSPACING, SPI_ICONVERTICALSPACING and
SPI_SETWORKAREA to not cause the icons to be reorganized.
Don't test out-of-bound values for SPI_SETKEYBOARDSPEED as behavior
differs accross Windows platforms.
On Win9x the maximum value for SPI_SETSCREENSAVETIMEOUT is 32767.
The registry keys and values stored in them for
SPI_ICONHORIZONTALSPACING and SPI_ICONVERTICALSPACING depend on the
Windows platform: ignore them.
No Windows platform seems to SPI_SETFASTTASKSWITCH: no longer test it.
The lParam of WM_SETTINGCHANGE is quite useless (even the MSDN says
so!) and varies accross Windows platforms. Ignore it.
Always check the SystemParametersInfoA return code as it fails in very
strange ways on some platforms. Skip unsupported settings.
Skip Unicode tests on platforms that don't support it.