Make sure the methods in our fake match the user's version of Net::HTTP

Specifically, this ensures that we won't add #continue_timeout= to rubies
that don't have it -- it was added to Net::HTTP in 1.9.3.

lib/fake_web/stub_socket.rb

@@ -1,7 +1,9 @@
 module FakeWeb
   class StubSocket #:nodoc:
 
-    attr_accessor :read_timeout, :continue_timeout
+    Net::BufferedIO.instance_methods.grep(/_timeout$/).each do |timeout|
+      attr_accessor timeout
+    end
 
     def initialize(*args)
     end

test/test_timeouts.rb

@@ -15,4 +15,19 @@ def test_sending_timeout_accessors_after_starting_session
     end
     assert_equal [5], timeouts.uniq
   end
+
+  def test_stub_socket_always_responds_to_read_timeout
+    FakeWeb.register_uri(:get, "http://example.com", :status => [200, "OK"])
+    http = Net::HTTP.new("example.com", 80)
+    http.get("/")
+    assert_respond_to http.instance_variable_get(:@socket), :read_timeout=
+  end
+
+  def test_stub_socket_only_responds_to_continue_timeout_under_193_or_later
+    FakeWeb.register_uri(:get, "http://example.com", :status => [200, "OK"])
+    http = Net::HTTP.new("example.com", 80)
+    http.get("/")
+    socket = http.instance_variable_get(:@socket)
+    assert_equal RUBY_VERSION >= "1.9.3", socket.respond_to?(:continue_timeout=)
+  end
 end