Add a new version (0.2.0) of the WAV package that works with julia 0.2.0

This now uses keywords instead of the Options package. It also replaces
deprecated features from julia 0.1.0 with the recommended equivalents in
julia 0.2.0.
Merge pull request #358 from dancasimiro/WAV

Add a new version (0.2.0) of the WAV package that works with julia 0.2.0