update CHANGELOG for 4.9.0
update CHANGELOG for 4.9.0

PikachuEXE/bullet,yakovenkodenis/bullet,jay3126/bullet,sho-h/brakefast,yakovenkodenis/bullet,danp60/bullet,eileencodes/bullet,hannahbot/bullet,PikachuEXE/bullet,theass/bullet,jay3126/bullet,rrosenblum/bullet,rrosenblum/bullet,rstacruz/bullet,sideci-sample/sideci-sample-bullet,danp60/bullet,sho-h/brakefast,dwb/bullet,flyerhzm/bullet,eileencodes/bullet,flyerhzm/bullet,rstacruz/bullet,flyerhzm/bullet,sideci-sample/sideci-sample-bullet,hannahbot/bullet,theass/bullet,dwb/bullet