Scattered corrections and improvements, and tests for python and julia versions

I have added a number of scattered corrections and improvements in both versions, including updates in the Readme.md files. I have also included tests in julia and made as compatible as possible with those in python. Still, there are some things to check.
I would prefer not to include this warning, since it leads to a lot of irrelevant output. Or maybe there should be a debug mode in which the warnings are shown.