- AttributeImpl is going to internally store the attribute id and
    value. saves 24 Bytes per attribute.
  - AttrImpl is allocated on demand for DOM compliance. inheriting
    from NodeBaseImpl now as it can have children (text and entityreference)
  - sharing name strings of unknown attributes for reduced memory consumption.
  There are still quite some FIXME's in the code though.
- NodeWParentImpl died as the only use (AttrImpl) got obsolete and
  was a wrong assumption anyway
- related code cleanups in DOM bindings. There is no point in adding
  1 line wrappers in xml/* if the method is completely unused and of
  no use inside khtml. moving the apropiate code directly in the DOM
  bindings.
- removed a lot of "virtual" specifications and made methods inline
  where apropiate. Now making EVERY method virtual is really a
  very, very bad idea. I did this cleanup already some time ago,
  not sure why they popped up again. there is NO point in making
  an accessor virtual that is never reimplement.
- ownerDocument() died in impl classes. using getDocument() everywhere.

result: 1260 less lines of code.

svn path=/trunk/kdelibs/; revision=129740