TIKA-1259 More Ogg mimetypes and fix-ups - Add dirac, tweak the default theora type, disable the FLAC-in-Ogg test pending an update, and add a common parent to all Ogg Audio types

git-svn-id: https://svn.apache.org/repos/asf/tika/trunk@1577180 13f79535-47bb-0310-9956-ffa450edef68