Add cli_dir to tempest config

Add the cli_dir option to the generated tempest config.  This is
required on platforms such as RHEL where the binaries are not in the
standard location.

Note that to be fully operational this requires [1] in tempest so that
the cli path is created correctly.

[1] https://review.openstack.org/#/c/34302/

Change-Id: Ic7369193f1434974366cfabc7550e8545de244cd
Update LVM autoextend config for RHEL6

Cinder clones are slightly larger due to some extra metadata.  RHEL6
will not allow auto-extending of LV's without this, leading to clones
giving hard-to-track disk I/O errors.

See https://bugzilla.redhat.com/show_bug.cgi?id=975052

Change-Id: I09a5e061a9665c5310383f9f9eb281bfdc8e416d
Merge "Update LVM autoextend config for RHEL6"
Merge "Add cli_dir to tempest config"