Per project forums added.

Permissions for forums management can be set in "Admin -> Roles & Permissions".
Forums can be created on the project settings screen ("Forums" tab).
Once a project has a forum, a "Forums" link appears in the project menu.
For now, posting messages in forums requires to be logged in. Files can be attached to messages.

git-svn-id: http://redmine.rubyforge.org/svn/trunk@529 e93f8b46-1217-0410-a6f0-8f06a7374b81

public/stylesheets/application.css

@@ -475,6 +475,8 @@ position: relative;
 margin: 0 5px 5px;
 }
 
+div.attachments {padding-left: 6px; border-left: 2px solid #ccc;}
+
 .overlay{ 
 position: absolute;
 margin-left:0;