Return some information about the screen. In particular, return a list of the horizontal resolution, the vertical resolution, the number of planes on the current screen (i.e. the bit depth), the bits per color supported by the hardware, the visual class (one of "StaticGray", "GrayScale", "StaticColor", "PseudoColor", "DirectColor" or "TrueColor") and a boolean indicating whether the display is color. The resolutions mentioned above should in theory be pixels per centimeter, rounded to the nearest integer. These parameters can be used for various workarounds or conditional decisions in a scwmrc to be shared among multiple machines.