add script to read out netcdf out per timeslice
new script huss_to_rh_timeslice.py changes:
- output double to float
- changed to ufz netcdf4 library to read out netcdf per timeslice and copy from input dataset more conveniently (copyDimensions, copyAttributes,...)
- with this comes new dependency of ufz python lib https://git.ufz.de/chs/python
- fillValue is set to -9999 to make the output directly compatible to mHM