taglib/taglib — pull request #211 by TsudaKageyu (2013-05-21 03:24:09+00:00)
Title: RIFF::WAV::Tag() returns TagUnion

Changed ```RIFF::WAV::Tag()``` to return ```TagUnion*``` instead of ```ID3V2::Tag*```. It was inconsistent with the ```File``` interface due to the backward compatibility.
```TagUnion``` is templatized. ```DoubleTagUnion``` and ```TripleTagUnion``` are defined, and further versions can be added easily if needed.