make rsync deal with sparse files efficiently
make rsync deal with sparse files efficiently

Signed-off-by: Lukas Pirl <46f1a0bd5592a2f9244ca321b129902a06b53e03@lukas-pirl.de>

caglar10ur/lxc,cjwatson/lxc,aeris/lxc,LynxChaus/lxc,hfuCN/lxc,caglar10ur/lxc,terceiro/lxc,GreatFruitOmsk/lxc,hallyn/lxc,LynxChaus/lxc,thmo/lxc,terceiro/lxc,hallyn/lxc,ysbnim/lxc,ss1h2a3tw/lxc,ss1h2a3tw/lxc,cjwatson/lxc,aeris/lxc,LynxChaus/lxc,hfuCN/lxc,ss1h2a3tw/lxc,aeris/lxc,federicobriata/lxc,federicobriata/lxc,hfuCN/lxc,thmo/lxc,GreatFruitOmsk/lxc,ysbnim/lxc,ysbnim/lxc,GreatFruitOmsk/lxc,federicobriata/lxc,terceiro/lxc,hallyn/lxc,caglar10ur/lxc,cjwatson/lxc,thmo/lxc