README: shuffle packages a bit
README: shuffle packages a bit

 - Move squashfs-tools to build dependencies.
 - Drop the protobuf stuff that's not needed to build lxd.
 - Replace lxc with liblxc1.
 - Add missing rsync dependency.

Signed-off-by: Stéphane Graber <089afc6d81f66f1168a9849e15660feae286e024@ubuntu.com>

georghopp/lxd,erikmack/lxd,lxc/lxd,jsavikko/lxd,Skarlso/lxd,stgraber/lxd,akshaykarle/lxd,pcdummy/lxd,hallyn/lxd,hallyn/lxd,atxwebs/lxd,lxc/lxd,Skarlso/lxd,stgraber/lxd,Skarlso/lxd,chrisglass/lxd,jsavikko/lxd,georghopp/lxd,chrisglass/lxd,erikmack/lxd,akshaykarle/lxd,ollie314/lxd,stgraber/lxd,ollie314/lxd,chrisglass/lxd,lxc/lxd,atxwebs/lxd,techtonik/lxd,atxwebs/lxd,stgraber/lxd,techtonik/lxd,lxc/lxd,hallyn/lxd,lxc/lxd,stgraber/lxd,stgraber/lxd,ollie314/lxd,erikmack/lxd,stgraber/lxd,techtonik/lxd,atxwebs/lxd,akshaykarle/lxd,hallyn/lxd,hallyn/lxd,pcdummy/lxd,Skarlso/lxd,mjeanson/lxd,pcdummy/lxd,mjeanson/lxd,georghopp/lxd,lxc/lxd,hallyn/lxd,mjeanson/lxd,lxc/lxd,jsavikko/lxd