added BattleExperienceMessage packet and tests

common/src/main/scala/net/psforever/packet/GamePacketOpcode.scala

@@ -532,7 +532,7 @@ object GamePacketOpcode extends Enumeration {
     case 0xb1 => noDecoder(VoiceHostKill)
     case 0xb2 => noDecoder(VoiceHostInfo)
     case 0xb3 => noDecoder(BattleplanMessage)
-    case 0xb4 => noDecoder(BattleExperienceMessage)
+    case 0xb4 => game.BattleExperienceMessage.decode
     case 0xb5 => noDecoder(TargetingImplantRequest)
     case 0xb6 => game.ZonePopulationUpdateMessage.decode
     case 0xb7 => noDecoder(DisconnectMessage)

common/src/main/scala/net/psforever/packet/game/BattleExperienceMessage.scala

@@ -0,0 +1,39 @@
+// Copyright (c) 2016 PSForever.net to present
+package net.psforever.packet.game
+
+import net.psforever.packet.{GamePacketOpcode, Marshallable, PlanetSideGamePacket}
+import scodec.Codec
+import scodec.codecs._
+
+/**
+  * Inform the client how many battle experience points (BEP) the player currently has earned.<br>
+  * <br>
+  * The amount of `experience` earned is an accumulating value.
+  * Whenever the server sends this packet, the value of this field is equal to the player's current total BEP.
+  * Each packet updates to a higher BEP score and the client occasionally reports of the difference as an event message.
+  * "You have been awarded `x` battle experience points."
+  * Milestone notifications that occur due to BEP gain, e.g., rank progression, will trigger naturally as the client is updated.<br>
+  * <br>
+  * It is possible to award more battle experience than is necessary to progress one's character to the highest battle rank.
+  * (This must be accomplished in a single event packet.)
+  * Only the most significant notification will be displayed.
+  * @param player_guid the player
+  * @param experience the current total experience
+  * @param unk na; always zero?
+  */
+final case class BattleExperienceMessage(player_guid : PlanetSideGUID,
+                                         experience : Long,
+                                         unk : Int)
+  extends PlanetSideGamePacket {
+  type Packet = BattleExperienceMessage
+  def opcode = GamePacketOpcode.BattleExperienceMessage
+  def encode = BattleExperienceMessage.encode(this)
+}
+
+object BattleExperienceMessage extends Marshallable[BattleExperienceMessage] {
+  implicit val codec : Codec[BattleExperienceMessage] = (
+    ("player_guid" | PlanetSideGUID.codec) ::
+      ("experience" | ulongL(32)) ::
+      ("unk" | uint8L)
+    ).as[BattleExperienceMessage]
+}