use a macro for the EbmlMaster iterator as it may differ between versions of libebml
use a macro for the EbmlMaster iterator as it may differ between versions of libebml

git-svn-id: eadd30ab68456b906a2cc85947e375706556b55c@39 a6f86f6d-0131-4f8e-9e7b-e335508773d5

Matroska-Org/libebml,Matroska-Org/libebml