Avoid compiling cadvisor statically for the docker image

This change does the following:
1. Derive cadvisor image from a stripped down busybox image. This is done to support DNS lookup. The image size is now ~20MB.
2. Log failures encountered while dumping to influxdb.
3. Handle critical failures in cadvisor gracefully without getting stuck.
Doesn't this produce the same behavior as before? If either thread runs into a fatal error it'd glog.Fatal no?