Vertex numbers can now be included in export to png
Use detectProperty for help
Print a detailed help message and then exit.
Made default number color static and final
Use ints to specify default number color
Methods to read color properties
Use instance fields to store the colors
Added setters for colors
Allow the different colors to be set using options
Don't use camel case for options
Also use an option to set the filename
Cast to Graphics2D is no longer needed
Allow the ends of the gradient to be set separately
Allow the gradient to be disabled
Allow to set the color of the outer edge of vertices