Removed dependency on ReportLab and moved to FPDF2 for writing PDFs. Reasons for doing so:
FPF2 is a better documented library;
Writing PDFs in FPDF2 is much more straightforward from a development perspective (no arbitrary string configuration lines to make it all work);
FPDF2 supports loading of PIL.Image images from memory where reportlab was causing issues if not written to file. This removes need for temporary files on disk when generating PDFs.
Removed dependency on ReportLab and moved to FPDF2 for writing PDFs. Reasons for doing so: