ROADMAP:
-------
    2.403: true type fonts
    2.404: better documentation in package Chart::Setting::Legacy.pod
    2.405: better legend drawing with additional settings and logos

    2.5  smooth graphics
    3.0: SVG backend


TODO's:
-------

General:
--------
- Reorganize the relationship between
  autoscale, 
  y_ticks, min_y_ticks, max_y_ticks, xy_plot, integer_ticks_only, skip_int_ticks,
  min_val, max_val
  and document it.
  (At the moment the autoscale is used as the default)

- Add chart type candlestick (used for stock exchange plots)

- include TrueType fonts

- 3-D charts

- add optional desciption text maybe with a picture (logo) ?

- svg, html and webp backend?



Plottype specific:
------------------
- Base class:
  : Some labels on the top of each axis not printed: i.e.,
    the graph goes to 100.6 but 100.6 is not printed. 
  : Define an option to force the first point sits at the left border of
    the graph, and the last point sits at the right border, without any spaces.
  : Add output for png without header as modperl generates the headers
    by itsself.
  : Add getopts(), 
  : Add dumpGetOpts(), i.e. list all options settings relevant for the 
                       module(s) currently in use, and/or all options defined.
     
- Composite:
  : When using bars in both, an option is necessary to define whether
    to put the bars above each other or to put aside.
  : Add an option to start x-ticks at the left (i.e. 0 point) side and
    end at the right side
  : When combining LinePoints and Mountain the use of
     min_val results in this error 
        "Use of uninitialized value in multiplication ..."
  : support up to 3 chart types - 
         for example: Mountain, StackedBars, LinesPoints 
    (The number of chart types should be flexible in general) 
  : Add option to limit the y-ticks to just one side
  : Define different brush_sizes for example with one Lines dataset 
    and one LinesPoints dataset. 
    
- pie chart:
  : Add a flat pie chart where the legend appears on the left
    of the chart, and the chart itself is about 50% smaller
  : Add an option to reduce or remove all the border elements on the left, 
    on the right and on the bottom
  : Allow to unset the title and remove the space occupied by the title,
    i.e., make the plot bigger
  : Add 3D appearance to the pies
  : Set arbitrary background color to the pie (and make the pie visible in
    the defined colors)
  : Setup the ray of the pie  

- Bars chart:
  : User would like to override the color of specific bars in a Chart::Bars graph.
  : Program should croak if a color is not defined for a bar.
  : Within one Bar graph, I have two datasets, but would like to change the 
    width of one of them (it should have a width of 1, to indicate a limit).
  : Within one Bar graph, I have two datasets, but would like to change the 
    width of one of them (it should have a width of 1, to indicate a limit).
  : Show values on each bar
  
- xy Plot:
  : Add a feature to limit what is shown on the x axis
  : include logarithmic x- and y-axis
  : Let plot arbitrary xy-functions in a defined area, like
     y=sin(1/x)+2*x

