The current rasops cursor implementation simply inverts the appropriate
framebuffer pixels by doing an XOR with an all-ones bit pattern. This
means the code has to read from the framebuffer which can be very slow.
Add an implementation that simply redraws the character covered by the
cursor with the foreground and background color swapped. While this
doesn't necessarily have the same visual result, most people probably
won't notice the difference (let's see). Use this implementation when
the RI_WRONLY or the RI_VCONS flags are set.
ok fcambus@