improve scrolling performance + remove deprecated APIs
improve scrolling performance + remove deprecated APIs

ermakovmaxim/lazysizes,phpgit/lazysizes,vasanthk/lazysizes,billybonz1/lazysizes,haidaxiaocong/lazyload,ermakovmaxim/lazysizes,ristoman/lazysizes,youprofit/lazysizes,cnweibo/lazysizes,aFarkas/lazysizes,youprofit/lazysizes,billybonz1/lazysizes,aFarkas/lazysizes,mattfili/lazysizes,phpgit/lazysizes,cnweibo/lazysizes,ristoman/lazysizes,mattfili/lazysizes,haidaxiaocong/lazyload,eric-seekas/lazysizes,vasanthk/lazysizes,eric-seekas/lazysizes