app fixes

fixes after 2/26/2013 meeting
- Language => Native Language
- Automatically set familiarity to 0 if the participant didn’t tap at
all
- Update consent screen to include approval dates
- Add another “Yes” response - “Yes - I didn’t know the song at all,
but I could tap it out after hearing it”
- Move Button position during task depending on handedness
- Add Play button to audio screen