Add upper boundary check on sizes and offsets in netcdf3 backend to prevent potential integer overflow problems. Also improved several potential problems in error handling cases
Add upper boundary check on sizes and offsets in netcdf3 backend to prevent potential integer overflow problems.
Also improved several potential problems in error handling cases

stcorp/coda,stcorp/coda,stcorp/coda,stcorp/coda,stcorp/coda,stcorp/coda,stcorp/coda