Fix serialization of class methods

According to collectiveidea#306, class methods were not having their payload object
set to the correct value.

Instead of being the classname of the target class, the payload object
was getting set to Class.

lib/delayed/syck_ext.rb

@@ -2,7 +2,7 @@ class Module
   yaml_as "tag:ruby.yaml.org,2002:module"
 
   def self.yaml_new(klass, tag, val)
-    klass
+    val.constantize
   end
 
   def to_yaml(options = {})

spec/yaml_ext_spec.rb

@@ -3,14 +3,14 @@
 describe "YAML" do
   it "should autoload classes" do
     lambda {
-      yaml = "--- !ruby/class:Autoloaded::Clazz {}\n"
+      yaml = "--- !ruby/class Autoloaded::Clazz\n"
       YAML.load(yaml).should == Autoloaded::Clazz
     }.should_not raise_error
   end
 
   it "should autoload the class of a struct" do
     lambda {
-      yaml = "--- !ruby/class:Autoloaded::Struct {}\n"
+      yaml = "--- !ruby/class Autoloaded::Struct\n"
       YAML.load(yaml).should == Autoloaded::Struct
     }.should_not raise_error
   end