Simple time tracking functionality added. Time can be logged at issue or project level.

There's no aggregation reports for now, it's just possible to see all time entries for a project or an issue.
A new "activities" enumeration is added.
Permission for a role to log time must be set (new "Time tracking" section in role permissions screen).

git-svn-id: http://redmine.rubyforge.org/svn/trunk@368 e93f8b46-1217-0410-a6f0-8f06a7374b81

app/models/project.rb

@@ -21,6 +21,7 @@ class Project < ActiveRecord::Base
   has_many :users, :through => :members
   has_many :custom_values, :dependent => :delete_all, :as => :customized
   has_many :issues, :dependent => :destroy, :order => "#{Issue.table_name}.created_on DESC", :include => [:status, :tracker]
+  has_many :time_entries, :dependent => :delete_all
   has_many :queries, :dependent => :delete_all
   has_many :documents, :dependent => :destroy
   has_many :news, :dependent => :delete_all, :include => :author