Quick Sequence Diagram Editor - usage:

  java -jar sdedit-{version}.jar [OPTIONS] [sdfiles]

  sdfiles are names of a files that, when specified, will be loaded
  for editing.
  
  OPTIONS:
  
    -s port        Starts the diagram server at the given port.
  
    -o output.png  a single sdfile must be specified and, without any user
                   interaction, the resulting diagram is written to
                   output.png, which is of course in PNG format.
