exec: don't s/\\n/\\r\\n/g when interactive
exec: don't s/\\n/\\r\\n/g when interactive

Closes #1652 (again :)

Signed-off-by: Tycho Andersen <10c18fcb898ee6b17d6575d444b125d10b3f4d6a@canonical.com>

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