* Add cgroup package

* Refactor procGgroup

* Add testdata generation

* Add v1 testdata generation

* Move scripts around

* Add integration test in CI

* Remove cgroup v1

* Move to cgroup struct

* Remove half-core test as it's redundant

golint is not supported anymore.  See
https://github.com/golang/go/issues/38968.

We already use both 'go vet' and 'staticcheck' which are maintained.

Copy the GitHub release notes into a NEWS.md file so that the release
notes are included in the actual git repo.  This way, they aren't hidden
away in GitHub, where they require an internet connection to access and
will be lost if GitHub ever goes away.  This also makes the release
notes be properly versioned; GitHub allows past release notes to be
edited, and there doesn't seem to be any record of what changed.

Finally, this allows packages to install the release notes into
/usr/share/doc/$pkgname/, as is the usual convention.

github.com/golang/protobuf/proto has been deprecated in favor of
google.golang.org/protobuf/proto, so migrate to the non-deprecated one.

Bump up the required Go version to 1.16 so that we can assume that Go
modules are enabled by default.  Go 1.16 is the latest end-of-life
release, so this makes it so that we support the latest end-of-life
release (1.16), the current maintainance release (1.17), the current
release (1.18), and future releases.  This the same approach we took
when we last bumped up the required Go version.

Also update the ci.yml file to test with these versions.