Rename [DelegatingPutFunction] IDL to [CustomNamedSetter] IDL

Rename [DelegatingPutFunction] IDL to [CustomNamedSetter] IDL
https://bugs.webkit.org/show_bug.cgi?id=77963

Reviewed by Adam Barth.

This patch renames [DelegatingPutFunction] IDL to [CustomNamedSetter] IDL,
for clarification and for naming consistency with [NamedGetter] and [CustomIndexedSetter].

No tests. No change in behavior.

* bindings/scripts/CodeGeneratorJS.pm:
(GenerateHeader):
(GenerateImplementation):
* bindings/scripts/CodeGeneratorV8.pm:
(GenerateHeaderNamedAndIndexedPropertyAccessors):
(GenerateImplementationIndexer):
(GenerateImplementationNamedPropertyGetter):
* bindings/scripts/test/TestInterface.idl:
* css/CSSStyleDeclaration.idl:
* dom/DOMStringMap.idl:
* html/HTMLAppletElement.idl:
* html/HTMLEmbedElement.idl:
* html/HTMLObjectElement.idl:
* page/History.idl:
* page/Location.idl:
* storage/Storage.idl:

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@107051 268f45cc-cd09-0410-ab3c-d52691b4dbfc