This fixes the problem of reading Wave-Files with odd chunk lengths.
The specification says that odd chunks have to be filled with a padding byte (value zero)
which is not included in the chunk length. So the next chunk is word aligned.
This also fixes the problem in pull request #220 but IMO in a way more aligned
with the wave spec.
To allow for malformed wave-files with no padding byte I check if the byte is zero before skipping it.