Add support for WAV

- add support for
  - TagLib::RIFF::WAV::File class
  - TagLib::RIFF::WAV::Properties class

- added swig code for TagLib::RIFF::WAV classes.
- added test code for reading/writing tags (ID3v2)
    to/from WAV files, including cover-arts.
- added a WAV-encoded audio file with ID3v2 tags for tests.
- added documentation.

- Note: support for RIFF-INFO tag is not included,
    TagLib 1.7 does not support this.
add test code for examples shown in the documentation

this is to ensure that examples actually work
(first run test code, then copy/paste to documentation)
add script to add/update tags in .wav test file
regenerate AIFF+WAV wrapper using swig 2.0.11 (#54)
fix spelling typo
Merge branch 'aiff' into wav
(to resolve merge conflicts)

Conflicts:
	taglib-ruby.gemspec
fix require path in test file
add c++ code to create/update tags in a WAV file

also add c++ code to dump tags from a WAV file
remove ruby code to create tags in a WAV file
re-enable test that was temporarily commented out
read picture file within picture test context
Merge pull request #57 from tchev/wav

Add support for WAV