Convert notebooks to 4 Python executable scripts

[JackKelly]

Convert to Python script which takes command line args or a config file

Have three separate scripts, all sharing a common config file, and all communicating through on-disk logs of completed files.

Option to continually keep checking (every hour?) for new files to download from EUMETSAT.

Sort and compress takes "no-delete" command line arg to say "leave uncompressed files on disk" so that the reprojection code doesn’t have to uncompress the file again.

Reprojection script takes two arguments:

• “don’t need to decompress Native file”
• “Delete Native file when done”

Write a fourth helper script which runs all three scripts, and passes the correct args.