There are cases where a private class may inherit an exportable member (e.g. ol.DebugTile_#getTileCoord comes from ol.Tile#getTileCoord). We want to avoid making these exportable.
This generates info for all symbols annotated with "@todo api" (when Plovr is replaced, this will become "@api"). Generated metadata is written to stdout. A separate process will handle the output.
Tim Schaub