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/show.rhtml

@@ -45,7 +45,7 @@
 		<% end %>		
 	</div>
   
-  <% if @subprojects %>
+  <% if @subprojects.any? %>
  	<div class="box">
 		<h3 class="icon22 icon22-projects"><%=l(:label_subproject_plural)%></h3>	
 		<%= @subprojects.collect{|p| link_to(p.name, :action => 'show', :id => p)}.join(", ") %>