fix job execution

On my Mac, the worker won't run properly if env is used in $workerCommand.

Jobs will get picked up by the worker, marked complete but not actually executed.

Also, the timeout for Process needs to be disabled.

I'd not picked these problems up before because I use supervisord to run the queue in production.
allow kernel.root_dir to be overridden

When you're running in an environment in which the source is symlinked on deployment (e.g. capistrano) you need to be able to override the kernel root as seen by the ContainerAwareJob because it changes with each deployment.
Merge pull request #36 from tonypiper/patch-3

allow kernel.root_dir to be overridden
Merge pull request #35 from tonypiper/patch-2

fix job execution
Merge remote-tracking branch 'origin2/master'