New branch for file structure change(#129) bug-fix for transcription(#84)

#129
- File structure and Recordings' metadata are changed
- This change will be automatically done by UpdateUtils using google account
- If the device has no google account, input dialog is triggered
- Recording's class model is changed to include 'versionName', 'ownerID'
- Recording's metadata now records 'versionName', 'ownerID'

#84
- Application-closing bugs while playing transcription player are fixe