Update inchi code to 1.0.6

[ghutchis]

The latest version of InChI is 1.0.6 - we need to update accordingly.

[nbehrnd]

Unable to recall if you or an other leading developer of openbabel attended the virtual meeting «InChI Days 2022» in April by InChI trust or/and are subscriber to the (low traffic) public discussion board, I would like to draw your attention to their technical meeting June 17--19 in Cambridge UK. Again, virtual attendance of the event is possible.

While the meeting wants to focus on "progress toward adding extended stereochemistry and tautomers", on Friday, Gerd Blanke chairs one session to clarify if ongoing work is going to be named InChI 1.07 (or 2.0).