Support for the new ContainerInfo (and Mesos<>Docker) about hadoop

[andrewrjones]

Would also like to see this. It doesn't look like Mesos supports the old way of defining containers any more.

[tarnfeld]

Ah yes we'll get to this! Maybe I'll work on it in the upcoming #MesosCon hackathon.

[andrewrjones]

Great, thanks Tom!

If you do get a chance to work on it then we should have some time to test it next week.

I had been looking through the code recently and it might not just be the Containerinfo code that needs to be updated. For example, mapred.local.dir is currently hard coded to System.getenv("MESOS_DIRECTORY") + "/mapred", but this doesn't make sense if we are running inside Docker, so it should at least be configurable.

I'm not sure if there are any other places in the code that make the assumption we are using a Mesos container, but thought I would mention this one in case you wasn't already aware.

[tarnfeld]

I've opened #68 which implements this, care to take a look @andrewrjones?