GWR in adding loop for 10 dates

GWR first script for one date in OR, task #364

Added 3 new models and nesting to GAM, task #361

Changes in the diagnostics plots, barplots.

Transform aspect in Eastness and Northness variables in the GAM.

Transformed the aspect variable and added GAM model closer to PRISM

GAM prediction added to the loop with RMSE calculation

Streamlining and slight changes to the loop to create subset dataset for different dates

Additional changes to the loop and format

Start of Task #361, modified code to subset for 10 dates