final version of gmted2010_res_x10/sc2a_dem_variables.sh

final version script gmted2010_res_x10/sc2_class_treshold_percent.sh and gmted2010_res_x10/sc3_class_treshold_density_merge.sh

first push for all the script used to create topographic variable

setting git repository for dem_variables folder

added in various previously uncommitted scripts