Fix net/http monkey patch, to prevent conflicts with other libraries.

Using the patch included in http://redmine.ruby-lang.org/issues/show/806

lib/couchrest/monkeypatches.rb

@@ -31,13 +31,19 @@ if RUBY_VERSION.to_f < 1.9
   class Net::BufferedIO #:nodoc:
     alias :old_rbuf_fill :rbuf_fill
     def rbuf_fill
-      begin
-        @rbuf << @io.read_nonblock(65536)
-      rescue Errno::EWOULDBLOCK
-        if IO.select([@io], nil, nil, @read_timeout)
+      if @io.respond_to?(:read_nonblock)
+        begin
           @rbuf << @io.read_nonblock(65536)
-        else
-          raise Timeout::Error
+        rescue Errno::EWOULDBLOCK
+          if IO.select([@io], nil, nil, @read_timeout)
+            retry
+          else
+            raise Timeout::TimeoutError
+          end
+        end
+      else
+        timeout(@read_timeout) do
+          @rbuf << @io.sysread(65536)
         end
       end
     end