adding 2 new extras: mp3_decode and soundfont

Here are the changes I made:

- updating version number
- extras now have minified versions as well
- adding timbre.mp3_decode.js in the extras folder
- adding timbre.soundfont.js in the extras folder
- adding jsmad in the extras folder
- adding test.mp3 in the misc/audio folder

You can check out the 2 new extras here:

- http://skratchdot.github.io/timbre.js/mp3_decode.html
- http://skratchdot.github.io/timbre.js/soundfont.html

NOTES:

- I'll be submitted a pull request for the gh-pages branch as well (if you choose to pull these in).
- I'm not sure why the 2 extras I added showed up first in the "extras" left navigation. I didn't mean for that to happen (not sure why it's not alphabetical- I can look into it if needed).
- The timbre.soundfont.js extra is kind of stupid at this point. I should make it work like most of the other timbre.js Object, but for now it's a singleton- and doesn't work "in the timbre way of doing things". I may revisit the way this is coded at some point down the line.