Porting the graph matchingdata structure and algorithms from Beam. These allow for efficient kekulisation though graph matching. I haven't added the kekulisation yet but as shown in the
tests of the patch all that is needed is to identify the atoms that should be next to a pi bond but aren't.
Diff:
Note - files will need migration.
Okay fixed up for new source roots.
Hmm - well I thought I fixed it but some files had the wrong name. Fixed now.
Looks good. Applied and pushed. Left a comment, though.