Ver. 0.4
Added significance indicators over data points.
xticlabels can be set for all kind of chart types.

Ver. 0.3
Added xgrid and ygrid commands for grid lines.

Ver. 0.2
Added a xticlabels command that allows to define
labels for the x-axis tics in bar graphs.

Ver. 0.1
Added a size command that allows to define the width and 
height of the chart. The default is 6.0x6.0 cm.

Ver. 0.0
First version: no changes
