Add feature to set default output device
Merge pull request #14 from kinushu/set_default_output_device

Add feature to set default output device
Add vendor/bundle for .gitignore
Renew dependencies. Hmm... why I add jeweler in it?
Add Gemfile in examples sub-directory.
Add fftw3 dependency for fft_shift_pitch.rb.
remove unused VERSION file.
Update ChangeLog for release 0.0.10.
Bump up CoreAudio::VERSION to 0.0.11.