Bug fixes

Small release bringing many bug fixes

• Bar chart's bind argument has been fixed.
• e_tooltip_choro_formatter tooltip formatter for choropleth maps added, thanks to Artem.
• Tooltip formatters correctly identify locale on UNIX systems, thanks to Artem.
• e_mark_point(), e_mark_line() and e_mark_area() no longer use grep(), which means the serie will only be matched with the exact same name. Thanks @shrektan for the reporting and PR (#80, #81).
• Multiple e_title now allowed.
• Multiple e_visual_map in timelines is now fixed.
• Corrected all links (or so I think).
• e_sankey fix thanks to Artem Klevtsov.
• Many dependencies removed, it is now much easier to install.