Added project module concept.

A project module (eg. issue tracking, news, wiki,...) is a set of permissions that can enabled/disabled at project level.
For each project, modules can be enabled on the project settings view ('Modules' tab).
This requires a specific permission: 'Select project modules' (if this permission is turned off, only Redmine administrators can choose which modules a project uses).

When applying this migration, all modules are enabled for all existing projects.

git-svn-id: http://redmine.rubyforge.org/svn/trunk@725 e93f8b46-1217-0410-a6f0-8f06a7374b81

test/unit/watcher_test.rb

@@ -58,7 +58,7 @@ class WatcherTest < Test::Unit::TestCase
     @user.mail_notification = false
     @user.save    
     @issue.reload
-    assert !@issue.watcher_recipients.include?(@user.mail)
+    assert @issue.watcher_recipients.include?(@user.mail)
   end
   
   def test_unwatch