Fixed bug 1166 (No mouse motion events while SDL_SetRelativeMouseMode() is active and holding the mouse button)

New API functions:
	SDL_SetWindowBrightness()
	SDL_GetWindowBrightness()
	SDL_SetWindowGammaRamp()
	SDL_GetWindowGammaRamp()
	SDL_CalculateGammaRamp()

Slightly speeded up event history processing each frame

 Jesse Anders      2011-03-05 23:30:09 PST

It seems that in Windows XP, setting SDL_GL_ACCELERATED_VISUAL to 1 actually
disables hardware acceleration and puts OpenGL in software mode.

In the source code, the corresponding WGL attribute is first set here:

*iAttr++ = WGL_ACCELERATION_ARB;
*iAttr++ = WGL_FULL_ACCELERATION_ARB;

Later, this code:

if (_this->gl_config.accelerated >= 0) {
    *iAttr++ = WGL_ACCELERATION_ARB;
    *iAttr++ =
        (_this->gl_config.accelerated ? WGL_GENERIC_ACCELERATION_ARB :
         WGL_NO_ACCELERATION_ARB);
}

Sets it again if SDL_GL_ACCELERATED_VISUAL has a value other than the default.

More importantly, the documentation I found states that
WGL_GENERIC_ACCELERATION_ARB asks for an MDC driver, which, although I don't
know much about this topic, doesn't seem like the correct choice here. As
mentioned previously, the end effect is that requesting hardware acceleration
in Windows XP actually forces the renderer into software mode (on my system at
least), which I'm guessing isn't the desired behavior.

Removed the NDS hack for ARGB1555 surfaces, since it's a general problem; added full color expansion for 16 bpp packed pixels.

Fixed bitmap order interpretation; SDL defaults to MSB ordering so a bitstream corresponds to a pixel stream.

The bitmap ordering is defined such that the numbering refers to the pixel index from left to right, and the number position refers to the bit position in the byte.

SDL_BITMAPORDER_4321 is the fourth pixel at the high bit and the first pixel at the low bit (LSBFirst)

SDL_BITMAPORDER_1234 is the first pixel at the high bit and the fourth pixel at the low bit (MSBFirst)