Beta Preview 26.6 changes:

- {ntnptr} references changed to {ntnidx}
- added nwc.ntnidx and nwc.drawpos objects
- nwc.newRef replaced by direct access to nwc.ntnidx.new() and
  nwc.drawpos.new()
- add {drawpos}:xyLyric
- extend {drawpos}:lyricSyllable to include separator as second return
  value
- add nwc.runContext