This add `make binary` to perform direct install libcontainer binaries inside
dockercore/libcontainer container instead of having to install dependencies and
run `make direct-install` on the host.
The `nsinit` binary will be placed into `bundles/nsinit`, and we ignore the
bundles directory from git.
Signed-off-by: Daniel, Dao Quang Minh <dqminh89@gmail.com>