Use a pure Go library for reading media tags

[ironsmile]

The current reliance of taglib is making the project much less portable than it should be. Cross-compiling is much harder as well.

To remedy this a pure go implementation of a library for reading media meta data could be used. There are a few possible candidates. They should be tested and evaluated with a big enough data set to see whether they perform similarly to taglib or not.

[ironsmile]

Possible candidate: https://github.com/bogem/id3v2