Move vool block compilation into constant generation

When the lambda is passed as argument, it must be moved. This triggers the generation of a corresponding parfait object (as before, and as for other constants) but now also triggers the code build. The code being the constant as it were
Also some more name fixes from renames

test/vool/test_class_expression.rb

@@ -10,10 +10,10 @@ module Vool
       @vool = ruby_tree.to_vool
     end
     def test_class
-      assert_equal ClassStatement , @vool.class
+      assert_equal ClassExpression , @vool.class
     end
     def test_method
-      assert_equal MethodStatement , @vool.body.first.class
+      assert_equal MethodExpression , @vool.body.first.class
     end
     def test_create_class
       assert_equal Parfait::Class , @vool.create_class_object.class
@@ -33,7 +33,7 @@ module Vool
     def assert_type_for(input)
       ruby_tree = Ruby::RubyCompiler.compile( as_test_main(input) )
       vool = ruby_tree.to_vool
-      assert_equal ClassStatement , vool.class
+      assert_equal ClassExpression , vool.class
       clazz = vool.create_class_object
       assert_equal Parfait::Class , clazz.class
       assert_equal :a , clazz.instance_type.names[1]

test/vool/test_method_expression.rb

@@ -13,9 +13,9 @@ module Vool
       @clazz.body.first
     end
     def test_setup
-      assert_equal ClassStatement , @clazz.class
+      assert_equal ClassExpression , @clazz.class
       assert_equal Statements , @clazz.body.class
-      assert_equal MethodStatement , method.class
+      assert_equal MethodExpression , method.class
     end
     def test_class
       assert_equal Parfait::Class , @clazz.create_class_object.class