Oxygen-17 0.7.2

This is just a small release to fix some issues with the (possibly) renamed *.so/*.dll files after removing Qt5 support. In case you were using Molsketch prior to version 0.7.1, it will ask you to update the corresponding settings at start up.

For Windows users, there will be an online installer, as in version 0.7.1, but this will now reside in a separate folder and not be updated as frequently as Molsketch itself. Updates will instead be made available in the online repository at github from which the installer will fetch them. Just start the installer and select the update option