Add ImageBuf::into_vec
Add ImageBuf::into_vec

dtwood/piston-image,huonw/image,mbrubeck/image,PistonDevelopers/image,ruud-v-a/image,bvssvni/image,PistonDevelopers/image,hetzge/image,nwin/rust-image,JaySon-Huang/image,lady-segfault/image,twoodford/image,TyOverby/rust-image,tomaka/image,xanium4332/image,theotherphil/image