TASK:Rename namespace

[johnhenley]

DNN Community Forums was forked from ActiveForums but a number of "activeforums" references remain. One to change is the module's namespace.

• Rename from DotNetNuke.Modules.ActiveForums
  To
  DotNetNuke.Modules.CommunityForums
• Update manifests
• Update scheduler items
• Update package/business class
• Update lucene to rebuild?
• This will be a breaking change for anyone who compiles against the forums module.