extracted silence_stream into its own file under webrat/selenium

I don't think silence_stream.rb should be stored under
core_extensions, because the way it's implemented, it simply is
no core extension. Also, a grep through webrat source shows that
silence_stream is only used inside the selenium support. This is
why I added webrat/selenium/silence_stream.rb and require it
*before* all other selenium related files in webrat/selenium.rb.
It's necessary to include it this early, because if mode is set
to :selenium, webrat/selenium.rb is required, which in turn
requires webrat/selenium/selenium_session.rb and silence_stream
must be available before selenium_session gets required because
selenium_session already wants to silence the stream.

lib/webrat/core/configuration.rb

@@ -1,17 +1,6 @@
 require "webrat/core_extensions/deprecate"
 
 module Webrat
-  
-  module SilentStream
-    def silence_stream(stream)
-      old_stream = stream.dup
-      stream.reopen(RUBY_PLATFORM =~ /mswin/ ? 'NUL:' : '/dev/null')
-      stream.sync = true
-      yield
-    ensure
-      stream.reopen(old_stream)
-    end
-  end
 
   # Configures Webrat. If this is not done, Webrat will be created
   # with all of the default settings.

lib/webrat/selenium.rb

@@ -1,6 +1,7 @@
 require "webrat"
 gem "selenium-client", ">=1.2.14"
 require "selenium/client"
+require "webrat/selenium/silence_stream"
 require "webrat/selenium/selenium_session"
 require "webrat/selenium/matchers"
 require "webrat/core_extensions/tcp_socket"

lib/webrat/selenium/application_server.rb

@@ -3,7 +3,7 @@ module Webrat
 
     class ApplicationServer
       
-      include Webrat::SilentStream
+      include Webrat::Selenium::SilenceStream
 
       def self.boot
         case Webrat.configuration.application_framework

lib/webrat/selenium/selenium_rc_server.rb

@@ -3,7 +3,7 @@ module Webrat
 
     class SeleniumRCServer
       
-      include Webrat::SilentStream
+      include Webrat::Selenium::SilenceStream
 
       def self.boot
         new.boot

lib/webrat/selenium/selenium_session.rb

@@ -22,7 +22,7 @@ module Webrat
 
   class SeleniumSession
     include Webrat::SaveAndOpenPage
-    include Webrat::SilentStream
+    include Webrat::Selenium::SilenceStream
 
     def initialize(*args) # :nodoc:
     end

lib/webrat/selenium/silence_stream.rb

@@ -0,0 +1,14 @@
+module Webrat
+  module Selenium
+    module SilenceStream
+      def silence_stream(stream)
+        old_stream = stream.dup
+        stream.reopen(RUBY_PLATFORM =~ /mswin/ ? 'NUL:' : '/dev/null')
+        stream.sync = true
+        yield
+      ensure
+        stream.reopen(old_stream)
+      end
+    end
+  end
+end