added simple svn statistics graphs, rendered using SVG::Graph

git-svn-id: http://redmine.rubyforge.org/svn/trunk@380 e93f8b46-1217-0410-a6f0-8f06a7374b81

app/models/repository.rb

@@ -18,6 +18,7 @@
 class Repository < ActiveRecord::Base
   belongs_to :project
   has_many :changesets, :dependent => :destroy, :order => 'revision DESC'
+  has_many :changes, :through => :changesets
   has_one  :latest_changeset, :class_name => 'Changeset', :foreign_key => :repository_id, :order => 'revision DESC'
   
   attr_protected :root_url