Description of problem:

WHen subscribing to CloudForms Beta using 'subscription-manager', 3 repositories are enabled by default:
 * CloudForms Application Engine (non-existent product)
 * CloudForms Cloud Engine
 * CloudForms System Engine

Since we don't support installing Cloud and System on the same system, we shouldn't enable the repos by default.  Additionally, we shouldn't enable Application Engine if it doesn't exist.

How reproducible:
 * Easy, use rhsm

Steps to Reproduce:
1. List available subscriptions
> subscription-manager list --available

2. Examine list of currently enabled repositories
> # yum repolist enabled
> repo id                         repo name                                     status
> rhel-6-server-cf-tools-1-rpms   Red Hat CloudForms Tools for RHEL 6 (RPMs)    0
> rhel-6-server-rpms              Red Hat Enterprise Linux 6 Server (RPMs)      7,104

3. Subscribe to CloudForms (or Beta)
> # subscription-manager subscribe --pool 8a9bf98636ea99cb0136f03c0fa037ed

4. Examine list of newly enabled repos

  
Actual results:

> # subscription-manager list --available
> +-------------------------------------------+
>     Available Subscriptions
> +-------------------------------------------+
> 
> <snip>
> 
> ProductName:            CloudForms Beta
> ProductId:              MCT2538
> PoolId:                 8a9bf98636ea99cb0136f03c0fa037ed
> Quantity:               2500
> Multi-Entitlement:      No
> Expires:                06/23/2012
> MachineType:            physical
> 
> <snip>
> 
> # subscription-manager subscribe --pool 8a9bf98636ea99cb0136f03c0fa037ed
> Successfully subscribed the system to Pool 8a9bf98636ea99cb0136f03c0fa037ed
> 
> # yum repolist enabled
> repo id                         repo name                                     status
> rhel-6-server-cf-ae-1-rpms      Red Hat CloudForms Application Engine (RPMs)  0
> rhel-6-server-cf-ce-1-rpms      Red Hat CloudForms Cloud Engine (RPMs)        0
> rhel-6-server-cf-se-1-rpms      Red Hat CloudForms System Engine (RPMs)       0
> rhel-6-server-cf-tools-1-rpms   Red Hat CloudForms Tools for RHEL 6 (RPMs)    0
> rhel-6-server-rpms              Red Hat Enterprise Linux 6 Server (RPMs)      7,104
> repolist: 7,104

Expected results:

Don't enable any repos.  The documentation for RHN classic recommends enabling specific repos.  This behavior should match for RHSM.

> # yum repolist enabled
> repo id                         repo name                                     status
> rhel-6-server-cf-tools-1-rpms   Red Hat CloudForms Tools for RHEL 6 (RPMs)    0
> rhel-6-server-rpms              Red Hat Enterprise Linux 6 Server (RPMs)      7,104
> repolist: 7,104