Convertdate

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* Repair Bahai intercalary days bug (13, thanks bchurchill)
* Replace pyephem, which is now in maintenance mode, with pymeeus.
* Remove shebangs and regularize licenses (thanks fabaff)
* Convert readme to ascii (16)

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* Bump requirements

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* Additional Jewish holidays (thanks, ohadeytan)
* Upload source distributions to Pypi (10)

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* Add Coptic (Alexandrian) calendar converter.
* Add explicit support for Python 3.6.

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* Change Exception thrown on illegal dates to ValueError.
* Add Comte's Positivist calendar.
* Bump requirement versions.

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* Fix Persian weekday order (thanks, meyt)