lxc-init kills all processes with SIGTERM
lxc-init kills all processes with SIGTERM

When lxc-init receives a SIGTERM, let's kill all the processes of
the pid namespace with kill -1. So the exit of the container will
happen gracefully with processes death cascade.

Signed-off-by: Daniel Lezcano <3211518dd4d87cb3f7ee12cb52e14b7fb2bc0446@fr.ibm.com>

ioops/lxc,Distrotech/lxc,armcc/lxc,ss1h2a3tw/lxc,QingweiPeterLan/cs188-lxc,glensc/lxc,aeris/lxc,bmoar/lxc,ioops/lxc,jirislaby/lxc,szaszg/lxc,JohnPeacockMessageSystems/lxc,armcc/lxc,weizhenwei/lxc,ojkastl/lxc_Patches,inokappa/lxc,virajs/lxc,hallyn/lxc,ostap/lxc,thmo/lxc,sapun/lxc,thmo/lxc,lazy404/lxc,tych0/lxc,efiop/lxc,hallyn/lxc,rldleblanc/lxc,Ponce/lxc,lazy404/lxc,sapun/lxc,Pelagicore/lxc,szaszg/lxc,bostjan/lxc,rowhit/lxc,lazy404/lxc,Distrotech/lxc,ysbnim/lxc,coconutpilot/lxc-gentoo-new,JohnPeacockMessageSystems/lxc,smoser/lxc,virajs/lxc,yubo/lxc,caglar10ur/lxc,federicobriata/lxc,glensc/lxc,hkjolhede/lxc,terceiro/lxc,DarknessBeforeDawn/lxc,akshaykarle/lxc,major/lxc,abstrakraft/lxc-android-lxc,ecarrara/lxc,raspberrypython/lxc,Distrotech/lxc,coconutpilot/lxc-gentoo-new,abstrakraft/lxc-android-lxc,potatosalad/lxc,ostap/lxc,LynxChaus/lxc,fwilson42/lxc,rldleblanc/lxc,tych0/lxc,Ponce/lxc,LynxChaus/lxc,GreatFruitOmsk/lxc,hfuCN/lxc,lisongmin/lxc,major/lxc,QingweiPeterLan/cs188-lxc,smoser/lxc,bmoar/lxc,ecarrara/lxc,jirislaby/lxc,glensc/lxc,regit/lxc,rowhit/lxc,ksperis/lxc,cjwatson/lxc,lisongmin/lxc,ecarrara/lxc,hallyn/lxc,bmoar/lxc,regit/lxc,cjwatson/lxc,weizhenwei/lxc,kylef/lxc,potatosalad/lxc,terceiro/lxc,akshaykarle/lxc,DarknessBeforeDawn/lxc,ss1h2a3tw/lxc,inokappa/lxc,federicobriata/lxc,ysbnim/lxc,tych0/lxc,christiaan/lxc,raspberrypython/lxc,usc-isi/lxc,armcc/lxc,ksperis/lxc,DarknessBeforeDawn/lxc,weizhenwei/lxc,bostjan/lxc,codebauss/lxc,ksperis/lxc,hfuCN/lxc,christiaan/lxc,usc-isi/lxc,christiaan/lxc,Ponce/lxc,sapun/lxc,ioops/lxc,cjwatson/lxc,fwilson42/lxc,yubo/lxc,smoser/lxc,efiop/lxc,hkjolhede/lxc,ysbnim/lxc,rldleblanc/lxc,regit/lxc,caglar10ur/lxc,fwilson42/lxc,ojkastl/lxc_Patches,Pelagicore/lxc,GreatFruitOmsk/lxc,QingweiPeterLan/cs188-lxc,virajs/lxc,thmo/lxc,terceiro/lxc,szaszg/lxc,federicobriata/lxc,efiop/lxc,hkjolhede/lxc,raspberrypython/lxc,usc-isi/lxc,aeris/lxc,major/lxc,ojkastl/lxc_Patches,abstrakraft/lxc-android-lxc,caglar10ur/lxc,abstrakraft/lxc-android-lxc,rowhit/lxc,smoser/lxc,lisongmin/lxc,codebauss/lxc,ss1h2a3tw/lxc,LynxChaus/lxc,jirislaby/lxc,yubo/lxc,bostjan/lxc,GreatFruitOmsk/lxc,kylef/lxc,aeris/lxc,codebauss/lxc,akshaykarle/lxc,Pelagicore/lxc,ojkastl/lxc_Patches,JohnPeacockMessageSystems/lxc,hfuCN/lxc