Changed Enumerations to use a Single Table Inheritance

* Added migrations to change Enumerations to an STI relationship
* Added TimeEntryActivity model (STI)
* Added DocumentCategory model (STI)
* Added IssuePriority model (STI)
* Added Enumeration#get_subclasses to get a list of the subclasses of Enumeration
* Changed Enumeration to use the STI type field instead of the opt field
* Changed Enumeration#opt to return the old opt values but with a deprecation warning.
* Removed Enumeration::OPTIONS
* Removed the dynamic named_scopes in favor of specific named_scopes.  Kept for
  compatibility reasons.
* Added Enumeration#default so each subclass can easily find it's default record.
* Fixed Enumeration#default to use the STI scoping with a fake default scope for finding Enumeration's default.
* Added a 'all' named scope for getting all records in order by position.
* Added Deprecation warnings to the old named_scopes in Enumerations.
* Moved various methods off of Enumeration and onto the concrete classes
* Changed the EnumerationsController to use types
* Updated the Enumeration list template
* Added has_many relationships to the Enumeration STI classes.
* Fixes for tests.

  #3007

git-svn-id: svn+ssh://rubyforge.org/var/svn/redmine/trunk@2777 e93f8b46-1217-0410-a6f0-8f06a7374b81

app/models/time_entry.rb

@@ -21,7 +21,7 @@ class TimeEntry < ActiveRecord::Base
   belongs_to :project
   belongs_to :issue
   belongs_to :user
-  belongs_to :activity, :class_name => 'Enumeration', :foreign_key => :activity_id
+  belongs_to :activity, :class_name => 'TimeEntryActivity', :foreign_key => 'activity_id'
   
   attr_protected :project_id, :user_id, :tyear, :tmonth, :tweek
 
@@ -37,7 +37,7 @@ class TimeEntry < ActiveRecord::Base
 
   def after_initialize
     if new_record? && self.activity.nil?
-      if default_activity = Enumeration.activities.default
+      if default_activity = TimeEntryActivity.default
         self.activity_id = default_activity.id
       end
     end