This package is now (mostly?) modifications for building on macOS as
well as some cleanups.

  - Add comments somehow about the big picture of approach on macOS.

    + PLIST.unix, and setting that to no on mac, does not make sense,
      as we are trying to treat mac like the underlying unix that it
      is.

    + geography/qgis has partial exorcism of mac bundle, but this
      removes that and changes to a different approach.  There's no
      rationale in the commit message.

    + File bugs and/or discuss upstream.  Are we fixing a bug?  Making
      a fundamentally different choice?  What is the long-term plan?

      It seems obvious that upstream should have cmake args to 1) not
      build the bundle and 2) build the normal stuff even on mac.

  - For the protobuf change, more clarity as there are enough hints to
    go figure it out, but it's not immediately clear on reading.

  - COMMIT_MSG

  - Test
