Vega-datasets

- Add `sp500-2000.csv`.

- Add `version` property to js module.

- Add `football.json`. Thanks to eitanlees!
- Add `penguins.json`.
- Add `seattle-weather-hourly-normals.csv`.
- Update `weather.csv` and `seattle-weather.csv` with better encoded weather condition, indicating more rain. Thanks to visnup!
- Update co2-concentration data and add seasonally adjusted CO2 field.
- Switch to ISO 8601 dates in `seattle-weather.csv`.
- Rename `weball26.json` to `political-contributions.json`.
- Convert `birdstrikes.json` to `birdstrikes.csv` and use ISO 8601 dates.
- Convert `movies.json` to use column names with spaces and use ISO 8601 dates.
- Remove `climate.json`.
- Replace `seattle-temps.csv` with more general `seattle-weather-hourly-normals.csv`.
- Remove `sf-temps.csv`.
- Remove `graticule.json`. Use graticule generator instead.
- Remove `points.json`.
- Remove `iris.json`. Use `penguins.json` instead.

- Strip BOM from `windvectors.csv`.

- Update `seattle-temps` with better sourced data.
- Update `sf-temps` with better sourced data.

- Add `ohlc.json`. Thanks to eitanlees!