Build 3.0.0.64 of xlsgen improves the fidelity of charts when duplicating sheets containing charts in XLSX files.

Among fidelity improvements are :
- better plot area position and size
- handling of multi-level labels (non-UI element)
- better gridlines
- better handling of chart-level data labels (as opposed to series-level data labels)
- reading of data point formattings
- better handling of horizontal bar charts (particularly the effect on l and b axis)

Also this build includes an improvement for rendering date types of the form [hh]:mm, [mm]:ss and [ss].