* Rename elements to mark as elements, i.e. Arc -> ArcElement
* Rename RectangleElement to BarElement
* Also updates options.elements.rectangle to options.elements.bar
* Add example of scriptable pie chart
* Add example of scriptable line chart
* Add example of scriptable polar area chart
* Add example of scriptable radar chart
Samples are supposed to show good practices and in most cases we don't use the time scale but require `Chart.bundle.js`, which is not correct. Instead, we should require the non-bundled version in its minified version (`Chart.min.js`). Paradoxically, time based examples don't use `Chart.bundle.js` but require moment manually side to `Chart.min.js`, which IMO is also the correct way since it allows users to configure and use moment globally (TZ, locales, etc.) and doesn't enforce a specific moment version.
Also remove the `data-labelling.html` example because we now have an [official plugin](https://github.com/chartjs/chartjs-plugin-datalabels) that implements this feature and don't want to deal with user custom code anymore.
The bar `backgroundColor`, `borderColor`, `borderWidth` and `borderSkipped` options are now scriptable (unit tests, docs and a basic sample). Also fix the gulp task that generates the documentation on Windows.
New `options.resolve` helper that determines the final value to use from an array of input values (fallback) and a given context and/or index. For now, only the bubble chart support scriptable options, see documentation for details.
Add scriptable options documentation and update the bubble chart dataset properties table with their scriptable and indexable capabilities and default values. Also move point style description under the element configuration section.
