Hello,

First of all, thank you for your work on this library.

Using HighMaps (through Highcharter), I recently encountered spelling mistakes in French departments having a grave accent, which causes the "è" to be wrongly encoded (e.g Ardčche instead of Ardèche), and prevents me from displaying external department-related data due to wrong key label when using the joinBy argument.

Exemple from JSFiddle with wrong spelling here (on the leftest department for example)

Do you know when will this be patched?

Have a nice day,