Make housekeeping interval dynamic, fist signal is resource usage.

If no resources are used by the container since the last housekeeping,
we double the housekeeping interval until --max_housekeeping_interval.
If usage was detected, we drop it back to the baseline
(--housekeeping_interval).

From my tests this reduces CPU usage in CoreOS from ~8% to ~3% with no
real loss of accuracy.

Fixes #159
Cleanup graph JS and don't show values below 0.
Adding the pprof HTTP service to cAdvisor.

This does not consume any resources unless the resources are queried.
Merge pull request #229 from vmarmol/pprof

Adding the pprof HTTP service to cAdvisor.
Merge pull request #227 from vmarmol/ui2

Cleanup graph JS and don't show values below 0.
Merge pull request #223 from vmarmol/dynamic-housekeeping

Make housekeeping interval dynamic, fist signal is resource usage.
Removing sampling and percentiles from interface.

Also removing all implementations.
Merge pull request #233 from vmarmol/master

Removing sampling and percentiles from interface.
Remove remaining parts of samples and percentiles.
Remove unused file.
Merge pull request #234 from vmarmol/obs

Remove unused file
Make dynamic housekeeping flag configurable
Merge pull request #237 from vmarmol/dyn

Make dynamic housekeeping flag configurable
Merge pull request #235 from vmarmol/rm

Remove remaining parts of samples and percentiles.
Adding all dependencies to Godeps.
Merge pull request #239 from vmarmol/deps

Adding all dependencies to Godeps.
Use inotify to watch for new containers.

This reduces cAdvisor CPU usage below 1% in my CoreOS system.

We also reduce global housekeeping to every 60s as a fallback in case we
miss an event.
Remove unused filter ContainerHandlers.
Wording changes to SubcontainerEvent comments
Merge pull request #238 from vmarmol/inotify

Use inotify to watch for new containers.