Split functionality out into lots of functions
Rewrote, encapsulating Excel and CSV specific code in objects
Now CsvOutput and ExcelOutput are constructed straight into a list of 'outputters'
get_box_url() now raises rather than using sys.exit
Moved error clearing code into function called by setup
Name chunking as paging consistently
Fix bug which split a row across lots of rows in .xls output
Merge pull request #24 from scraperwiki/mega-refactor

Refactor, encapsulate format-specific code in objects