Output file suffix always .mp3 regardless of chosen container format

[Vidrep]

If AC-3, flac or wav is selected, the encoded output file suffix is always mp3.

[scottmc]

I think the .mp3 always being at the end of the filename is due to the preferences setting. It defaults to something like
/boot/home/music/%a/%n/%a - %n - %k - %t.mp3
which tells it to add .mp3 to the end of the name. This should get fixed if/when the preferences are redone soon. We will set the output suffix to default to what "other" operating systems would normally name that type of file.

[scottmc]

Does this with OGG as well.

[scottmc]

This issue in oggencoder is fixed by #52