Features:
Added Network Stats to Container Info. It still not exposed via the HTTP UI.
Bug fixes:
1. Modified docker handler to use libcontainer.GetStats instead of quering the fs package.
2. cAdvisor will not stall if any of its core operations fail.
3. cAdvisor will safely ignore any inactive or leaked docker containers. When containers are leaked cgroup state exists but docker is not aware of them.
Adding utils package
Fix raw cgroups handler.
Fixed bugs introduced in previous patches.
Addressed comments. Another series of bug fixes.
Modified the docker driver and lmctfy driver to skip containers they cannot handle.
Removed NotActive error message from container package.
Imporved error messages.
Ignore non '/docker' containers in the docker driver.
Docker ListContainers will work only for the '/docker' container.
Merge pull request #96 from vishh/network_stats

Bug fixes and introduces network stats.