Generate PDF based templates, and fill them in from data objects

1. Someone with a form does a Print to PDF with all the spaces blank
2. They get a data structure (schema) from another app or API
3. Both the PDF and the data are loaded into the Form8sn UI, and they:
   • Place boxes on the PDF page surfaces
   • Add rules to partition the data and repeat PDF pages (plus running totals and the like)
4. This is exported to a command file embedded in a modified version of the PDF
5. A programmer can then pass the command file and data to the Form8sn SDK to get back a finished PDF

The PDF generation phase should be as fast as possible. If we can, it should be a streaming process so we don't need to load the whole PDF template or output into memory.

• PDFSharp - A modified version of the main project (so I can add or specialise bits)
• PortableGdi - A minimal version of System.Drawing to support PDFSharp. Based on GNU Portable.Net base libraries.
• BasicImageFormFiller - GUI app to take scanned paper forms (in JPEG) and fill them in from arbitrary data, based on examples.
• TestApp - Console app scratch space
• PdfSharp.Charting - Currently unused.
• Form8snCore - File formats and filtering to produce PDFs from project files
• WebFormFiller - .Net MVC website and JS app for editing Form8sn projects

• Write some documentation
• Ensure the core PDFsharp and Form8snCore don't use GDI+ (important)
  • Portable system.drawing
  • JPEG reading and writing ( Portable.Drawing.Imaging.ImageFormats.JpegReader.Load )
  • Font reading & metrics ( PdfSharp.Drawing.XFontSource.GetOrCreateFromFile )
  • Remove defunct platform specific calls in PDFsharp.
• Handle PDFs as input
• Decode PDF forms so we can use existing 'boxes'
• Embed Form8sn instructions in PDF files and handle those? (not important)
• Web-based form editor?
• Full suite of tests

To add new prefixes, see Form8snCore.DataExtraction.MappingActions.GetDataAtPath and Form8snCore.HelpersAndConverters.DataPickerBuilder