Undid preliminary NetCDF code + added proper NetCDF code

[ghost]

• removed netcdf code i have written so far because was crappy
• added proper netcdf code, in particular : proper sqlalchemy objects representing netcdf_meta and netcdf_data tables, holding the metadata of the netcdfs (one row per netcdf file, in the table netcdf_meta), respectively the actual data of the netcdfs (as tiles, all in one table, called netcdf_data)
• ingestion script ingest_netcdf.py that ingests both metadata + actual data. the ingestion script can be run with "python ingest_netcdf.py [path of netcdf]"