Linode with support for DNS setup and extra partitions

This patch adds new functionality to the linode module:

- nodes can now be found by name and not only linode id
- DNS can be optionally setup automatically (with parameters domain_host, domain_name and domain_email)
- extra partitions can be optionally created through the 'partitions' parameter

Documentation and examples were added accordingly. This module was tested on Linode and worked as expected. There are not backward incompatible changes, so no scripts will be broken.