NEX part1 accuracy assessment mosaicing for 1000x3000km with python code

modifications, run 10 NEX accuracy assessment 1000x3000km

examining available output for 1500x4500km

running part 1 accuracy assessment NEX run 1000x3000km

initial commmit for functions part1 fro global scaling and accuracy assessment

splitting code for script part global assessment of accuracy, removing functions

NEX global assessment run 10 1000x3000km tiles part1

paper proof multi-timescale Figure 11 modifications

subsampling script, major modifications to solve issues related to North America runs

data preparation script, modifications to solve subsampling issue in North America