Improve best rated selector

[DayS]

If user asked for two langages, we have to select the best subtitle according to the language order.

For example :
Requested : spa, fre

Possible responses are ( * is the selected response ) :

[spa, 0] *
[spa, 0]

[spa, 0]
[spa, 4] *

[fre, 0]
[fre, 4] *

[fre, 0]
[spa, 0] *
[spa, 0]

[fre, 0]
[spa, 0]
[spa, 4] *

[fre, 7] *
[spa, 0]
[spa, 4]