Adds Rackspace Cloud Files support to quickstart

Adding in Rackspace Cloud Files support to pelican-quickstart so users can do:

<pre>
$ make cf_upload
</pre>

Files will be uploaded to Cloud Files using swift, from the [python-swiftclient](https://github.com/openstack/python-swiftclient) (available in PyPI) package.

<pre>
$ pip install python-swiftclient
</pre>

The swift option "-c" has been added so that only changed files will be uploaded.