added wiki page

app/models/wiki_page_version.rb

@@ -0,0 +1,12 @@
+class WikiPageVersion < ActiveRecord::Base
+  belongs_to :wiki_page
+  belongs_to :updater
+  
+  def updater_name
+    User.find_name(updater_id)
+  end
+
+  def pretty_title
+    title.tr("_", " ")
+  end
+end