Pre-release, tagged because the following release will deprecate a few functions.

• e_labels to easily add labels.
• Mapbox support see e_mapbox.
• Improved e_scatter.
• Improved e_toolbox.
• Fixed e_axis (and corresponding e_x_axis and e_y_axis) bugs.
• e_add added for nested data.
• e_showtip_p and e_hidetip_p fixed.
• e_focus_adjacency_p and e_unfocus_adjacency_p proxies to highlight adjacent nodes (on graph/network) added.
• Deprecation of texture related functions in favour of echarts4r.assets.
• e_single_axis added, works with e_scatter.
• e_text_style added, to customise global fonts.
• e_angle_axis now takes serie argument, see example.
• Improved documentation of many functions.

First iteration of the graphic low-level API:

• g_graphic_g
• g_group_g
• g_image_g
• g_text_g
• g_rect_g
• g_circle_g
• g_ring_g
• g_sector_g
• g_arc_g
• g_polygon_g
• g_polyline_g
• g_line_g
• g_bezier_curve_g

• Added actions that can be tied to buttons.
• Added the ability to add buttons.
• Added e_arrange & e_connect to connect charts interactions and visualise them together.
• Better supprot for radial, angle, and polar charts.
• Callbacks added e_on and e_off.
• e_map_custom added to work with custom registered maps.
• e_datazoom takes a toolbox argument to optionally not the dataZoom toolbox element.
• Much improved documentation
• e_map and e_map_3d no longer require the serie argument.
• e_mark_*: The serie argument of the mark family functions (i.e.: e_mark_point) can now take a vector and if left NULL the point is marked on all series.