Add nsjail service for Tizen distribution

Add nsjail service for Tizen distribution

Tizen will use nsjail as application container by using USER Namespeace.

If creating new user namespace, the new user can get admin(root) privilege in the namespace,
and can use several kernel resource by creating other namespaces.

However, the new user namesapce cannot access unprivilged resource in original namespace.
For that, Tizen nsjail service creates some resources (directories for cgroup, and bind mount tmp directories) for the new user namespace.

cf) Each Tizen App has each smack label.
    Unfortunatly, nsjail does not consider such issue for bind mount.
    For that, at this moment, we create new user's uid based folder name for each application.
    In the future, the folder name should be created on basis of Tizen package name.