* Bare start on CSV support
* Move core of CSV importer to operations
* More validations, break out validation function
* Validate dates and TaskList; convert errors to list of dictionaries
* Finish upsert code, and documentation
* Print msgs from the mgmt command, not the operations module
* Handle BOM marks
* Handle both in-memory and local file objects
* Update readme
* Working browser-upload view
* Bail on incorrect headers
* Fix default values and finish example spreadsheet
* Change column order, update docs
* Update index.md for RTD
* First round of responses to PR feedback
* Restore independent summaries/errors/upserts properties
* PR responses
* Split off reusable date validator into separate function
* Fix URLs append
* General test suite for CSV importer
