ColorPicker - Function that lets user select a color to use.

[Dav]

I have update this function to a smaller and simple looking version to use in a drawing program.  It no longer uses a pre-made  image that has to be decoded, but uses a predefined 16-color general palette (shows gradients too).  You can change those to any colors you want to display.  The function works the same way as the previous versions does.

NOTE: QB64-PE does have a great color picker _COLORCHOOSERDIALOG, but on my PC there was a conflict using it sometimes when running under _FULLSCREEN, so I updated this function to use again. 

-Dav