Adds a SoftLayer Object Framework that supports Bare Metal and Virtual Servers

This is a large change, but adds an Object Framework to the SoftLayer API gem.  The goal of the Object Framework is to provide a high-level model for entities in the SoftLayer Environment.  The high-level model is implemented in terms of the lower level API calls.

This release includes high-level models for Servers, both Bare Metal servers, and Virtual Servers.  For both it provides some basic functionality for upgrading and canceling servers.  It also provides classes for ordering servers.