add number of player to replay vault

[shalkya]

Would be great to add the possibility to choose the number of player in the replay we want to appear in the replay vault.
This way we could select only 1v1 custom games that are being played on faf mod (and not all team games); also would permit to see all 1v1 being played, ie : faf mods (beta, nomads....) and ladder together.

Would maybe need to be sure observer are not counted in the number of players.

would also help a lot 1v1 casters.