Added observers to watch model objects for mail delivery instead of calling Mailer.

* Added an IssueObserver to watch when Issues are created
* Added a JournalObserver to watch when Journals are created (Issue updates)
* Added a NewsObserver for News items.
* Added a DocumentObserver for Document notifications.
* Setup IssuesController#new to use the IssueObserver.
* Setup IssuesController#edit to use the IssueObserver.
* Setup IssuesController#bulk_edit to use the JournalObserver.
* Removed the Mailer call in Changeset#scan_commit_for_issue_ids, the
  JournalObserver will handle it.
* Removed Mailer calls in MailHandler in favor of the Observers.

  #2659

git-svn-id: svn+ssh://rubyforge.org/var/svn/redmine/trunk@2637 e93f8b46-1217-0410-a6f0-8f06a7374b81

app/controllers/news_controller.rb

@@ -45,7 +45,6 @@ class NewsController < ApplicationController
       @news.attributes = params[:news]
       if @news.save
         flash[:notice] = l(:notice_successful_create)
-        Mailer.deliver_news_added(@news) if Setting.notified_events.include?('news_added')
         redirect_to :controller => 'news', :action => 'index', :project_id => @project
       end
     end