EXP: bind mount ruby and lxc for faster experiments

Before this patch, ruby and lxc were downloaded using apt-get,
which took some time (in addition to the time required for
doing an apt-get update). For a large number of containers (>4),
the time it took to install ruby and lxc on the containers was
too long.

This patch locates the various files needed by lxc and ruby on
the host's filesystem and bind mounts them into each container.
This way, network connection is not necessary to run the
experiments, and the container setup process is much faster.

This patch depends on the hosts's ruby interpreter being version
1.9.1. For other versions, the code to bind mount the ruby files
will need to be manually amended.