Lets-plot

Added
- geocoding package

Fixed
- NPE on geom_tile when data contains null-s.
- The order of values in the `limits` parameter on discrete scales is ignored.
- Livemap is not shown in GGBunch.

Added
- Plugin for IntelliJ IDEA / PyCharm is available. For more info see the plugin homepage: [Lets-Plot in SciView](https://plugins.jetbrains.com/plugin/14379-lets-plot-in-sciview).

Changed
- Plots build time reduced (up to 4X)

Added
- `geom_smooth`: automatic sampling when n>1000 and the method is LOESS.

Fixed
- 'map_join' fails when the `map` argument is a dictionary [[130](https://github.com/JetBrains/lets-plot/issues/130)]

Changed
- HTML output was modified allow better integration with PyCharm.

Removed
- The deprecated method 'load_lets_plot_js()'.

Added
- Support for interactive maps.
- The `as_discrete()` function.
- Polynomial regression of an arbitrary degree (the`lm` smoothing method) in *geom_smooth*.
- `axis_tooltip`, `axis_tooltip_x`, `axis_tooltip_y` parameters in `theme()`
- Kaggle and Datalore notebook demos.

Fixed
- Severe performance degradation when using discrete scales [[119](https://github.com/JetBrains/lets-plot/issues/119)].
- Opaque background to better support PyCharm dark theme [[121](https://github.com/JetBrains/lets-plot/issues/121)].
- Auto-detection of a Kaggle environment.
- Limits on the maximum plot size [[115](https://github.com/JetBrains/lets-plot/issues/115)].
- Installation instructions for Windows users [[118 MinGW](https://github.com/JetBrains/lets-plot/issues/118)].

Changed
- More slick shape for tooltips on the axis.

Added
- Python 3.6 support.
- Windows platform support.
- SVG/HTML export to file.
- Offline mode for Jupyter notebooks.
- Support for cloud-based notebooks like Google Colab and Datalore.
- JVM Maven artefacts released.

Fixed
- Tooltip on `geom_rect` and `geom_vline`.
- Error when date-time series contains `NaT` value.

Changed
- Optional `load_lets_plot_js()` function is now deprecated.
- Initialisation call `LetsPlot.setup_html()` is now mandatory in Jupyter.

Fixed
- tooltip not showing in geom_polygon