Draft: Fix orekit data repo URL

See merge request !6

Support loading orekit data from Python library

See merge request !5

only merge after orekit/orekit-data!4 : update URL in conda environments

https://gitlab.orekit.org/yzokras/orekit-data.git -> https://gitlab.orekit.org/orekit/orekit-data.git

Example: <frozen importlib._bootstrap>:488: DeprecationWarning: builtin type __JArray_string_iterator has no __module__ attribute

With default value False in order not to break compatibility with existing code

TODO after merge of orekit/orekit-data!4 : replace the URL by https://gitlab.orekit.org/orekit/orekit-data.git !!

TODO after merge of orekit/orekit-data!4 : replace the URL by https://gitlab.orekit.org/orekit/orekit-data.git !!

Correction for swapped apogee/perigee in some examples. Removal of %pylab inline to use %matmplotlib inline and separate plt object.

Make setup_orekit_curdir optionally load data from folder

See merge request !3

Issue 423: absolutedate_to_datetime behaviour during leap second

Closes #423

See merge request !2