Initial draft of Makefile

- Makefile to download T/S climatologies and decompress into ascii
- .gitignore to ignore tarfiles and ascii directory with unpacked data
Checksums for ascii data
Skeleton python script WOA05_to_netcdf.py

- Handles two arguments, nothing more.
Implemented ascii reader

- Reads entire file and reshapes to appropriate shape.
Implemented writing of netcdf

- T and S attributes obtained from dictionaries.
  - Need to extend to cover other variables.
Added rules to Makefile to generate netcdf files
Added tool to calculate md5sum by variable

- Since the md5sum of a netcdf file is reproducible across
  re-generation of the file, we have to hash the individual
  variable data.
Added md5sums for netcdf files
Added hash of meta data in netcdf files