Minor format changes and clean up to code

Corrected errors in RMSE calculation and added plots to view results

made minor changes to PRISM variables

changed RMSE and AIC code in GAM script

updated GAM script for tmax

added initial R script with GAM regression for tmax (one date)

added test script for days missing from our MOD11A1 OR holdings

cleaned up file permissions

added in various previously uncommitted scripts