Updated changelog for 2.1 release
Updated changelog for 2.1 release

CURA-1326

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