Can't save Ogg Vorbis files due to bug in TagLib

[jangler]

See #5, which is now "fixed" in that Taffy refuses to save Ogg Vorbis files due to the possibility that TagLib might corrupt them in the process. The problem is that now Taffy can't edit Ogg Vorbis files at all, even ones that would not be corrupted, since the conditions under which corruption happens are unknown.

This issue will remain open until the underlying bug is fixed or worked around in either taglib-ruby (https://github.com/robinst/taglib-ruby/issues/82) or, more likely, TagLib itself (https://github.com/taglib/taglib/issues/864).

I guess I'll call this issue an "enhancement" because it's only a limitation, even though it's necessitated by a bug in a dependency.