Version 9, patch 10

* Fixed problems with player.Ping
* Added (subject to update_interval also):
plugin.IsSquadLocked function
plugin.GetSquadLeaderName function
player.MaxPing, player.MinPing, player.AveragePing and player.MedianPing
* Added update_interval setting, for setting how frequently the following
  var.* values are updated:
server.BulletDamage
server.FriendlyFire
server.GunMasterWeaponsPreset
server.IdleTimeout
server.SoldierHeatlh
server.VehicleSpawnAllowed
server.VehicleSpawnDelay