Add option to rename container to lxc-clone
Add option to rename container to lxc-clone

This commit adds an -R, --rename option to lxc-clone to rename a container. As
c->rename calls do_lxcapi_rename() which in turn calls do_lxcapi_clone() it
seemed best to implement it in lxc-clone rather than lxc-snapshot which also
calls do_lxcapi_clone(). Some additional unification regarding the usage of
return vs exit() in main() was done.

Signed-off-by: Christian Brauner <94aca18939fc64aa4df96ea8cb026da8a2e1541a@gmail.com>

szaszg/lxc,LynxChaus/lxc,bostjan/lxc,lisongmin/lxc,ioops/lxc,jirislaby/lxc,bmoar/lxc,christiaan/lxc,rowhit/lxc,tych0/lxc,hfuCN/lxc,terceiro/lxc,bostjan/lxc,Ponce/lxc,yubo/lxc,DarknessBeforeDawn/lxc,virajs/lxc,fwilson42/lxc,JohnPeacockMessageSystems/lxc,DarknessBeforeDawn/lxc,ksperis/lxc,hallyn/lxc,Pelagicore/lxc,terceiro/lxc,rldleblanc/lxc,ecarrara/lxc,lisongmin/lxc,jirislaby/lxc,LynxChaus/lxc,federicobriata/lxc,Pelagicore/lxc,armcc/lxc,rldleblanc/lxc,GreatFruitOmsk/lxc,federicobriata/lxc,aeris/lxc,virajs/lxc,christiaan/lxc,akshaykarle/lxc,Ponce/lxc,caglar10ur/lxc,caglar10ur/lxc,yubo/lxc,Distrotech/lxc,QingweiPeterLan/cs188-lxc,akshaykarle/lxc,rowhit/lxc,JohnPeacockMessageSystems/lxc,cjwatson/lxc,federicobriata/lxc,thmo/lxc,armcc/lxc,ioops/lxc,GreatFruitOmsk/lxc,jirislaby/lxc,armcc/lxc,Pelagicore/lxc,cjwatson/lxc,Distrotech/lxc,hallyn/lxc,tych0/lxc,yubo/lxc,ysbnim/lxc,ysbnim/lxc,bmoar/lxc,thmo/lxc,ksperis/lxc,bmoar/lxc,hfuCN/lxc,LynxChaus/lxc,tych0/lxc,raspberrypython/lxc,DarknessBeforeDawn/lxc,aeris/lxc,Ponce/lxc,fwilson42/lxc,GreatFruitOmsk/lxc,hfuCN/lxc,rowhit/lxc,virajs/lxc,rldleblanc/lxc,thmo/lxc,fwilson42/lxc,ksperis/lxc,bostjan/lxc,raspberrypython/lxc,caglar10ur/lxc,JohnPeacockMessageSystems/lxc,szaszg/lxc,ss1h2a3tw/lxc,ecarrara/lxc,Distrotech/lxc,ioops/lxc,ss1h2a3tw/lxc,lisongmin/lxc,cjwatson/lxc,QingweiPeterLan/cs188-lxc,ss1h2a3tw/lxc,aeris/lxc,christiaan/lxc,terceiro/lxc,akshaykarle/lxc,QingweiPeterLan/cs188-lxc,ysbnim/lxc,hallyn/lxc,ecarrara/lxc,raspberrypython/lxc,szaszg/lxc