Support for timeline added

• e_clean removed as it was not of use anymore.
• e_list added to pas raw list of options.
• Improved e_color_range helper.
• e_lm & e_loess now support group_by.
• e_scattter scaling much more robust with new arguments. Also not takes an optional symbol argument.
• Jitter points with e_scatter
• e_append adapated to work with new scatter-family of function (scaling).
• e_lines_gl added.
• Improved examples.
• Can now register multiple maps with e_map_regiter.
• Error handling in e_loess and e_lm to better work with groups.
• e_capture to capture events not implemented.
• e_bands to add confidence bands.
• Added example of heatmap with geo.
• Fixed bug where the background color was not applied with e_color.
• e_scatter size forced to numeric to avoid buggy character vector caused by apply function.
• Forces webgl rendering for e_globe, e_scatter_gl and e_flow_gl.
• Groups are now ordered in order to ensure match across series when using timeline = TRUE.
• e_theme now also accepts default.
• auritus theme added.
• bar.width argument renamed to bar_width in e_histogram.
• e_map_3d and e_map correctly assign name argument.
• Axis and tooltip formatters helpers added e_tooltip_item_formatter & e_axis_formatter, thanks to Artem Klevtsov.
• e_error_bar added to plot error bars.
• Ability to specify icons in e_legend.
• e_aria added to enable generating Accessible Rich Internet Applications.