fix bug with player not getting updated on disconnect (related to issue #24)

jint version downgraded for better stability (also locked the engine instance as it's not thread safe)
updated readme
remove vpn detection from application configuration as it's now in a seperate plugin
defaulted webfront bind URl to all interfaces
readd the custom say name
added visibility percentage to AC

Plugins/Stats/Models/EFClientKill.cs

@@ -31,6 +31,7 @@ namespace IW4MAdmin.Plugins.Stats.Models
         public DateTime When { get; set; }
         public double Fraction { get; set; }
         public bool IsKill { get; set; }
+        public double VisibilityPercentage { get; set; }
         // http://wiki.modsrepository.com/index.php?title=Call_of_Duty_5:_Gameplay_standards for conversion to meters
         [NotMapped]
         public double Distance => Vector3.Distance(KillOrigin, DeathOrigin) * 0.0254;