Started implementing sqlFrontend for admin interface

- It will allow export/import of database dumps
- It shall aid fetching database updates
- Currently only export is working
Updated sound submodule
Fixed playing soundfiles

I filtered the soundfile types in the wrong place.
This led to .ogg being unavailable, if .mp3 was the choosen download type.
Soundfile types are now filtered in these occasions:
- When resolving ondemand loading of soundfiles.
  In this case we filter for the type that the browser preferrs.
- When downloading individual soundfiles.
  In this case we filter for the type choosen in the wordByWord download options.
Halted development of SQL operations in admin interface

- Other issues are more pressing
- I'll resume this later, and will than remove the disable part in query/sql.php
  and the error-message in sqlFrontend.php