Improve Dutch translation
Improve Dutch translation

Many consistency issues, mainly with capital letters.

Contributes to issue CURA-570.

ynotstartups/Wanhao,Curahelper/Cura,ynotstartups/Wanhao,hmflash/Cura,fieldOfView/Cura,hmflash/Cura,fieldOfView/Cura,Curahelper/Cura