Added the ability to archive projects:

* Only administrators can archive/unarchive projects.
* Once archived, the project is visible on the admin project listing only. It doesn't show up anywhere else in the app. Subprojects are also archived.
* Archive/unarchive preserve everything on the project (issues, members, ...).
* A subproject can not be unarchived if its parent project is archived.

git-svn-id: http://redmine.rubyforge.org/svn/trunk@549 e93f8b46-1217-0410-a6f0-8f06a7374b81

app/views/projects/destroy.rhtml

@@ -1,11 +1,11 @@
 <h2><%=l(:label_confirmation)%></h2>
 <div class="box">
 <center>
-<p><strong><%= @project.name %></strong><br />
+<p><strong><%= @project_to_destroy.name %></strong><br />
 <%=l(:text_project_destroy_confirmation)%></p>
 
 <p>
-    <% form_tag({:controller => 'projects', :action => 'destroy', :id => @project}) do %>
+    <% form_tag({:controller => 'projects', :action => 'destroy', :id => @project_to_destroy}) do %>
     <%= hidden_field_tag "confirm", 1 %>
     <%= submit_tag l(:button_delete) %>
     <% end %>