Don't re-install cloud-init for centos7 images

The centos7 images come with the base version of cloud-init already
installed.

---
$ virt-inspector CentOS-7-x86_64-GenericCloud-GA-7.0.1406_01.qcow2
...
      <application>
        <name>cloud-init</name>
        <version>0.7.5</version>
        <release>10.el7.centos.1</release>
        <arch>x86_64</arch>
      </application>
...
---

I think this is a hang-over from early rhel7 images that didn't have
it.

Change-Id: Idf488942222d9e6bca4d66f04f5af42e6707944d
Allow for multiple image outputs from raw source

When uploading images to multiple clouds it is possible that the same
image will be needed in multiple formats to accomodate hypervisors
across clouds. Update disk-image-create's -t flag to take a list of
desired output image formats so that a single disk-image-create can
output all of the desired image formats.

Change-Id: If121b2342ae888855ba435aa3189f039e985b812
Consolidate lsb_release source-repositories

Each distro had its own copy of the file, but they were all the
same and it's actually installed in redhat-common so it belongs
there.

Change-Id: Iad15f39fd28d1c4e20d30dcb2eb0ae6f2fa2b015
Force empty $TMPDIR inside the chroot

There are some situations (use of libpam-tmpdir) where the $TMPDIR is
defined per user, so any sudo call will define an specific $TMPDIR for
the root user which doesn't exist inside the chroot.

Change-Id: I866651fed520007506c7be83837d3791ed9f2235
Closes-Bug: #1330290
Remove first-boot.d support

After being deprecated two releases ago, finally remove any reference
for the support of first-boot.d

Change-Id: I08d67404ef48cad61db3b18fb86e970abfa5d2b6
Merge "Don't re-install cloud-init for centos7 images"
Merge "Remove first-boot.d support"
Merge "Force empty $TMPDIR inside the chroot"
Merge "Consolidate lsb_release source-repositories"
Merge "Allow for multiple image outputs from raw source"