v0.0.4

This release includes one fix:
* Get cgroups directory from current process, not from init process

This release fixes checkpoint/restore behavior with mounted cgroups.
Also it includes various minor features and bugfixes. Full list of changes:

* Add signal API to Container interface
* Update github.com/opecontainers/specs to 5b31bb2b7771e5074a4eb14eca432da1ca5182d6
* Don't set /proc/<PID>/setgroups to deny in Go1.5
* Add debug message when unable to execute criu
* Remove reference to nsinit
* Replace dind with smaller script
* integration: show criu logs in a error case
* tests: dump/restore a container with cgroups
* Simplify and fix os.MkdirAll() usage
* Change default state directory to /run/oci
* Add TESTFLAGS to Makefile targets
* Update README.md to correct comment about spec and user
* Only add network info if NEWNET is set
* Fix files not closed in mountinfo parsing function
* signal: Fix leak
* test: propagate the error to the caller
* Swap check for systemd booted to use go-systemd method
* Vendor github.com/coreos/go-systemd/util
* Use /proc/self/exe as default for InitPath
* Adapt code to go-systemd/dbus v3
* Update github.com/coreos/go-systemd/dbus to v3
* typo: tempory -> temporary
* bring the loopback interface up
* systemd integration with container runtime for supporting sd_notify protocol
* Remount /sys/fs/cgroup as RO if MS_RDONLY was passed in m.Flags
* Update maintainers guide
* Create symlinks for merged cgroups
* ct: give criu informations about cgroup mounts
* Fix subsystem path with abs parent
* avoid infinite loop with GCCGO

Fix release
Changes:
* Substract source mount from cgroup dir

runc/libcontainer release

Most notable changes are about mounting cgroups inside container.

Changes(from docker/libcontainer v2.2.1 https://github.com/docker/libcontainer/releases/tag/v2.2.1):
* Fix handling name= cgroups
* Tests for mounting cgroups
* Substract bindmount path from cgroup dir
* Add cgroup mount in the recommended config
* Correct tmpfs mount for cgroup
* Fix error when memory cgroup not mounted
* the data type should be int8 for ppc64le
* Remove deserialization tests.
* Add oom-kill-disable support for systemd
* Fixing test step for memory swappiness
* Remove sample configs from libcontainer
* Rename SystemProperties to Sysctl and make it available in the runc config
* Treat -1 as default value for memory swappiness.
* Remove apparmor profile generation from libcontainer
* Fix build tags
* libcontainer: user: update tests for GetAdditionalGroups
* libcontainer: user: fix GetAdditionalGroupsPath to match API
* Windows: Factor out seccomp
* checkpoint/restore commands support 'file-locks' option.
* Windows: Factor out CloseExecFrom
* Allow hyphen in "id" (based on `cwd` pathname)
* libcontainer: gofmt pass
* Fix panic in seccomp test on error
* Remove nsinit from libcontainer README.md