Adds email notification on wiki changes (#413). It's disabled by default and can be enabled in application settings.

git-svn-id: svn+ssh://rubyforge.org/var/svn/redmine/trunk@2749 e93f8b46-1217-0410-a6f0-8f06a7374b81

app/views/mailer/wiki_content_updated.text.plain.rhtml

@@ -0,0 +1,8 @@
+<%= l(:mail_body_wiki_content_updated, :page => h(@wiki_content.page.pretty_title), 
+																			 :author => h(@wiki_content.author)) %>
+<%= @wiki_content.comments %>
+
+<%= @wiki_content.page.pretty_title %>:
+<%= @wiki_content_url %>
+<%= l(:label_view_diff) %>:
+<%= @wiki_diff_url %>