The lib module is the subset of cAdvisor that the kubelet vendors, and the
kubelet does not need cAdvisor to watch for OOMs. It reads /dev/kmsg itself
and supplies container_oom_events_total on its own, so the OOM machinery does
not belong in lib.

Remove watchForNewOoms and the per-container OOM counter from lib/manager, and
move the kmsg reader (utils/oomparser) from lib to the root module, which the
binary depends on. lib no longer imports github.com/euank/go-kmsg-parser.

The cAdvisor binary keeps its OOM events and the container_oom_events_total
metric. cmd/internal/api now runs the OOM watcher, feeds OOM and OOM-kill
events to the event manager, and wraps the manager so the prometheus collector
reports the per-container OOM count.

Signed-off-by: Davanum Srinivas <davanum@gmail.com>