optimize searchalbum/searchmusic searchsimilar scheme

[dmelo]

Now after searchsimilar is called, N other calls are made, each one to load one element given by searchsimilar.

Make it so that searchsimilar already returns those elements IF they exists on database. So that, the only ones that are meant to be searched afterwards, are those that are not on the database yet.

This improvement will decrease the number of requests needed to print an incBoard table.