Update import_data_netcdf.m

Recently I found that different versions of netcdf libraries save data in different format. 
This now can automatically detected by present version of code.
Update import_data_netcdf.m

One more line added which was missed in previous change.
This let MATLAB know the format of netcdf version.
Merging improvements to Matlab import_data_netcdf

By Sanat Tiwari, IPR, India