Upgrade to Rails 2.0.2

Upgraded to Rails 2.0.2, except that we maintain

   vendor/rails/actionpack/lib/action_controller/routing.rb

from Rail 1.2.6 (at least for now), so that Routes don't change. We still
get to enjoy Rails's many new features.

Also fixed a bug in Chunk-handling: disable WikiWord processing in tags (for real this time).

test/functional/application_test.rb

@@ -19,7 +19,7 @@ class ApplicationTest < Test::Unit::TestCase
   
   def test_utf8_header
     get :show, :web => 'wiki1', :id => 'HomePage'
-    assert_equal 'text/html; charset=UTF-8', @response.headers['Content-Type']
+    assert_equal 'text/html; charset=UTF-8', @response.headers['type']
   end
   
   def test_connect_to_model_unknown_wiki