added NDVI model and more diagnostics to soil moisture state space model
added NDVI model and more diagnostics to soil moisture state space model

EcoForecast/SoilMoisture,rkstan/SoilMoisture,parevalo/SoilMoisture,rkstan/SoilMoisture,parevalo/SoilMoisture,rkstan/SoilMoisture,parevalo/SoilMoisture,EcoForecast/SoilMoisture,parevalo/SoilMoisture,rkstan/SoilMoisture,EcoForecast/SoilMoisture,EcoForecast/SoilMoisture