Output data used to generate chart

[petebrew]

Request from Tom Swetnam:

The ability to export data used by the chart as CSV/Excel tables. This would be one table per FHX file with the following columns:

• Year
• Sample depth
• Recorder depth
• Count of trees recording fires
• Count of trees recording other injuries
• Count of early earlywood scars
• Count of middle earlywood scars
• etc etc for all variables

[petebrew]

Much of this functionality is already implemented in the summary tab of FHRecorder so I'm deferring a complete resolution to this issue until v2.1.