Alright -- most of this code is just more cleanups, and the bugfix part of it

Alright -- most of this code is just more cleanups, and the bugfix part of it
is relatively small.  Basically it took a while for me to be convinced that the
ID3v2 location was always going to be before the FLAC data stream pointer.  I've
added a check to make sure that it stays that way, but I don't expect us to
actually hit that code.

BUG:120578

git-svn-id: svn://anonsvn.kde.org/home/kde/trunk/kdesupport/taglib@503614 283d02a7-25f6-0310-bc7c-ecb5cbfe19da