New Color objects

[Makuna]

Several new color objects have been added. These include the following...
Rgb16Color - This RGB color object only requires 16 bits to store the color information. It uses a standard 565 encoding ; 5 bits for red, six bits for green, and 5 bits for blue. This is useful for in memory storage of large image data to reduce data size while retaining maximum color definition. It will auto convert to other color objects and can be used directly when calling strip.SetPixelColor().
Rgb48Color - This RGB color object uses 48 bits to store the color information. It uses 16 bits per element providing higher resolution of color information. This will be used with future support for LEDs that can directly consume this higher resolution. It will auto convert to most other color objects as long as there is no data loss. This means converting to RgbColor (24 bits) or Rgb16Color is not directly possible.