correctly select WRF build type based on new toolkit_comp_family function in tools/toolkit.py; bring get_openmp_flags into Toolkit class so it can use toolkit_comp_family  as well

adjust easyblock and add patch file to make WRF build procedure support netCDF-4.2 with seperate netCDF-Fortran libs

fix module name and class name for netCDF-Fortran, and make sure netcdf_fortran module will be found

add easyblock and example easyconfig for netCDF-Fortran, and make sure class is found (replace '-' with '_' for obtaining class name)