flake8 cleaning

Using the following options:

    [flake8]
    ignore = E123,E124,E128,E201,E202,E241
    max-line-length = 100
Replaced argparse with docopt
Tidied and refactored choices around pickle vs json
Split write-pickle into its own script operation
Generalised read mechanism across input kinds
Add an iterator over feature collection producing polygons
Added CSV writer capability
Added capability to read from CSV tz->polygon map