Update CHANGELOG for #471, #475, #489, #495
Update CHANGELOG for #471, #475, #489, #495

yujinakayama/mail,jeremyevans/mail,jonkgrimes/mail,zacholauson/mail,0x00evil/mail,missive/mail,carsonreinke/mail,pjskennedy/mail,EdwardPantoja/mail,kjg/mail,agaridata/mail,jeremy/mail,EdwardPantoja/mail,pushrax/mail,agaridata/mail,benmmurphy/mail,kert-io/mail,kainlite/mail,pascalbetz/mail,schneems/mail,jonkgrimes/mail,wktk/mail,planio-gmbh/mail,schepedw/mail,zacholauson/mail,schepedw/mail,kaineer/mail,pjskennedy/mail,benmmurphy/mail,jeremyevans/mail,smallspark/mail,owenr/mail,carsonreinke/mail,pushrax/mail,kert-io/mail,wktk/mail,Schniz/mail,smallspark/mail,mikel/mail,kjg/mail,0x00evil/mail,kaineer/mail,jeremy/mail,schneems/mail