Regenerate SWIG wrappers using swig 2.0.12

The only "real" change is that ASSOCIATE_FILESYSTEM_ENCODING was added
to aiff and wav as well. The reason they were not there before was that
they were branched before that change was made on master.
Update copyright year
Merge pull request #61 from robinst/swig_2.0.12

Regenerate SWIG wrappers using swig 2.0.12
Add missing test files to gemspec
Update CHANGES.md for 0.7.0
Bump version to 0.7.0
Fix GitHub PR number in CHANGES.md