Squashed commit of the following:

commit b51f5f8bf3bd6b157a14ab82ce25afe842fa0847
Author: Richard Wall <richard.wall@clusterhq.com>
Date:   Tue Aug 5 17:58:43 2014 +0100

    Link to the flocker-cli installation instructions

commit 9f970413e69ac798ebac48f1456ae1cbcfa04bad
Author: Richard Wall <richard.wall@clusterhq.com>
Date:   Tue Aug 5 17:57:28 2014 +0100

    A further note about disk space requirements

commit 70e869edb10228b015c6c6b2a766981b9dc9858d
Author: Richard Wall <richard.wall@clusterhq.com>
Date:   Tue Aug 5 17:52:37 2014 +0100

    Add a note about minimum disk space requirements

commit dafa40a5ba2a18f1aa836fc2f814f18f95fe2ea0
Author: Richard Wall <richard.wall@clusterhq.com>
Date:   Tue Aug 5 17:11:34 2014 +0100

    remove the temporary test I was using to check that this works

commit 0b69d2fc27738fb60bc2221c59f5590dbdbd4aad
Author: Richard Wall <richard.wall@clusterhq.com>
Date:   Tue Aug 5 17:10:56 2014 +0100

    discard stdout and stderr when running zfs list
Merge pull request #438 from ClusterHQ/tutorial-disk-space-requirements-422-2

Add notes about the disk space required by the tutorial virtual machines.

Fixes #422.