added missing hashCode() implementation, fixes #34
Merge pull request #45 from beckchr/master

Issue #34: added missing hashCode() implementations
Merge branch 'master' of https://github.com/mpatric/mp3agic

# By Christoph Beck
# Via Christoph Beck (1) and Michael Patricios (1)
* 'master' of https://github.com/mpatric/mp3agic:
  added missing hashCode() implementation, fixes #34