Change SoundRecorder microphone icon background

Fixes #692.
* Background of the SoundRecorder is now transparent, thus matches the background color of the rest of the app.
* Renamed icons to match our naming scheme.

![soundrecorder](https://f.cloud.github.com/assets/1933325/1366626/76eb4590-38dc-11e3-9547-c168c217e5d3.PNG)

Test run incoming.