switched plots to .png due to weird background colour issue (drought phases not showing up in pdfs on windoze)

built 3 models: synthetic model and 2 based on SPRG water practices survey data; added enhanced water efficiency uptake model (bit of a kludge in places), you wouldn't start from here gov. Output a load of new & updated plots

re-arranged plots so clear which model is being used; saves out plots without model labels for papers etc