Improved warning message when a compound without a 3D structure is provided.

Change-Id: If4a0a6427a9d71e76f59eaeea6205468899d5d6f
Signed-off-by: Egon Willighagen <egonw@users.sourceforge.net>
Recognition of projection based stereochemistry.

Change-Id: I449ccaaf5909efb1f45377c4391362b64140b15c
Signed-off-by: Egon Willighagen <egonw@users.sourceforge.net>