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* Add GOES-18 differential and real time integral fluxes; changes
GOES-R integral flux source to CCMC's HAPI API
* Add configuration by user config file in the configparser INI
format, replacing placement of config values in config.py. This
fixes the pip deployment issue whereby a user could not easily
update the code configuration.
* Add --ExportConfig option to opsep & idsep. Users may use this to
prepare a custom configuration.
* Fix: Create necessary output directories instead of crashing if
they don't exist