* set active_vfn so un-saved views can be tracked
* fix typo
* expose the active_vfn to the command env
* merge lint.Note and lint.Pos and make it/them a namedtuple
* add support for note.kind and use it prefix messages instead of the ctx - this brings it back in line with the original design and allows linting a single file by its path
* update `note-x` to work with the merging of lint.Note and lint.Pos
* add support for note.kind