persistent namespaces

Today I merged support for persistent namespaces to unshare(1). The persistent namespace does not require any running process with in the namespace and it's possible to enter the namespace by nsenter(1). For example let's create a new UTS namespace and set a different hostname within the namespace: # hostname ws # touch /root/ns-uts # unshare --uts=/root/ns-uts # hostname FooBar # exit Now there i