lxc-ls: Cache groups and show bygroup in autostart
lxc-ls: Cache groups and show bygroup in autostart

This makes sure we only query lxc.group once and then reuse that list
for filtering, listing groups and autostart.

When a container is auto-started only as part of a group, autostart will
now show by-group instead of yes.

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

weizhenwei/lxc,hallyn/lxc,virajs/lxc,hallyn/lxc,caglar10ur/lxc,GreatFruitOmsk/lxc,weizhenwei/lxc,codebauss/lxc,bmoar/lxc,regit/lxc,thmo/lxc,hfuCN/lxc,LynxChaus/lxc,hkjolhede/lxc,rldleblanc/lxc,regit/lxc,raspberrypython/lxc,rowhit/lxc,bmoar/lxc,ecarrara/lxc,ksperis/lxc,Ponce/lxc,lazy404/lxc,jirislaby/lxc,ss1h2a3tw/lxc,lazy404/lxc,aeris/lxc,major/lxc,efiop/lxc,bostjan/lxc,christiaan/lxc,ioops/lxc,ioops/lxc,armcc/lxc,DarknessBeforeDawn/lxc,virajs/lxc,sapun/lxc,thmo/lxc,raspberrypython/lxc,JohnPeacockMessageSystems/lxc,Pelagicore/lxc,bmoar/lxc,lisongmin/lxc,hfuCN/lxc,rowhit/lxc,JohnPeacockMessageSystems/lxc,terceiro/lxc,QingweiPeterLan/cs188-lxc,lazy404/lxc,akshaykarle/lxc,Distrotech/lxc,caglar10ur/lxc,hfuCN/lxc,cjwatson/lxc,hkjolhede/lxc,armcc/lxc,terceiro/lxc,QingweiPeterLan/cs188-lxc,lisongmin/lxc,bostjan/lxc,JohnPeacockMessageSystems/lxc,fwilson42/lxc,Distrotech/lxc,major/lxc,LynxChaus/lxc,ksperis/lxc,Ponce/lxc,tych0/lxc,GreatFruitOmsk/lxc,szaszg/lxc,ysbnim/lxc,ioops/lxc,Pelagicore/lxc,virajs/lxc,ecarrara/lxc,armcc/lxc,terceiro/lxc,bostjan/lxc,lisongmin/lxc,DarknessBeforeDawn/lxc,weizhenwei/lxc,federicobriata/lxc,yubo/lxc,ecarrara/lxc,QingweiPeterLan/cs188-lxc,rowhit/lxc,szaszg/lxc,raspberrypython/lxc,ss1h2a3tw/lxc,federicobriata/lxc,Distrotech/lxc,GreatFruitOmsk/lxc,sapun/lxc,tych0/lxc,rldleblanc/lxc,DarknessBeforeDawn/lxc,jirislaby/lxc,caglar10ur/lxc,Pelagicore/lxc,tych0/lxc,codebauss/lxc,ysbnim/lxc,ysbnim/lxc,cjwatson/lxc,aeris/lxc,Ponce/lxc,rldleblanc/lxc,akshaykarle/lxc,codebauss/lxc,jirislaby/lxc,hkjolhede/lxc,yubo/lxc,efiop/lxc,hallyn/lxc,thmo/lxc,christiaan/lxc,yubo/lxc,sapun/lxc,fwilson42/lxc,federicobriata/lxc,major/lxc,christiaan/lxc,szaszg/lxc,ss1h2a3tw/lxc,fwilson42/lxc,LynxChaus/lxc,efiop/lxc,cjwatson/lxc,ksperis/lxc,akshaykarle/lxc,aeris/lxc,regit/lxc