move sound in pageGameMain

[jeromeetienne]

• currently in pageGameRound
• cant play sound at the end as pageGameRound is killed
• additionnaly this is silly reinit of the sound

[jeromeetienne]

• in fact, they should even be above that
• sound which are constant for the whole game must be init once and that it
• maybe init them and do a globalSoundLayer

[jeromeetienne]

done in lib/soundPool.js