[WIP] Bz1133132 add new models to reporting

Adding several cloudy models to reporting:

* Flavors
* Availability Zones
* Security Groups
* Cloud Tenants
* Cloud Resource Quotas
This line is testing if class_by_assoc_class_name is a subclass of class_by_assoc_name.

In the case of a relationship to AvailabilityZone like the following:
```
belongs_to :ext_management_system, :foreign_key => :ems_id, :class_name => "EmsCloud"
```
class_by_assoc_class_name will be EmsCloud and class_by_assoc_name will be ExtManagementSystem.
I am open to any better variable names.

About < operator, see [Core API / Module / #<]
(http://www.ruby-doc.org/core-1.9.3/Module.html#method-i-3C)