Added volumes from support: Fixes #9

- Added new volumesFrom parameter in Docker.runDetached
- Use volumesFrom when the system property oki-docki.running.from.container is defined

In order to work this requires a couple of things in the container running the jenkins slave:

- defining a set of volumes to ensure that everything required could be shared with the container making the build: the workspace and tmp directory
- set the oki-docki.running.from.container system property to the name of the container running the slave

In my [swarm docker image](https://github.com/ggtools/jenkins-swarm-docker) I moved `java.io.tmpdir`inside the defined volume and defined the container name from the environment variables.