Vanilla palette sprites

If there is a palette set in the image already, this will take precedence over the first line swatch. In other words, image imports must be either in 24bit color with a swatch, or in lower color depth with a properly ordered palette. FF3usME does not seem to load 24bit images saved by GraphicsGale in my experience, so setting up the palette order properly is the way to go.

Most reliable way in my experience to get things working smoothly is:
- Draw the swatch
- Set image to 24bit color (all frames -> color depth -> 24bpp/truecolor)
- Set image immediately back to 16 color (all frames -> color depth -> 4bpp/16 color)
- Save and import into FF3usME

Setting to 24bpp will remove all existing palette data in the image, since 24bpp is not a palettized format. Then returning to 16 color mode will create a new palette by reading the colors in the image, starting left to right at the top and moving down. The first thing it encounters is the swatch, so it populates all those colors first, in order.