New buff framework (player implementation)

Get rid of `iConditionBitFlag` in favor of a system of individual buff
objects that get composited to a bitflag on-the-fly.
Buff objects can have callbacks for application, expiration, and tick,
making them pretty flexible. Scripting languages can eventually use
these for custom behavior, too.

TODO:
- Get rid of bitflag in BaseNPC
- Apply buffs from passive nano powers
- Apply buffs from active nano powers
- Move eggs to new system
- ???

src/Buffs.cpp

@@ -0,0 +1,30 @@
+#include "Buffs.hpp"
+
+#include "PlayerManager.hpp"
+
+using namespace Buffs;
+
+static void timeBuffUpdate(EntityRef self, BuffStack* buff, int type) {
+
+    if(self.kind != EntityKind::PLAYER)
+        return; // not implemented
+    
+    Player* plr = (Player*)self.getEntity();
+    if(plr == nullptr)
+        return;
+    
+    INITSTRUCT(sP_FE2CL_PC_BUFF_UPDATE, pkt);
+    pkt.eCSTB = buff->id; // eCharStatusTimeBuffID
+    pkt.eTBU = type; // eTimeBuffUpdate
+    pkt.eTBT = (buff->buffClass <= BuffClass::CONSUMABLE); // eTimeBuffType 1 means nano
+    pkt.iConditionBitFlag = plr->getCompositeCondition();
+    self.sock->sendPacket((void*)&pkt, P_FE2CL_PC_BUFF_UPDATE, sizeof(sP_FE2CL_PC_BUFF_UPDATE));
+}
+
+void Buffs::timeBuffUpdateAdd(EntityRef self, BuffStack* buff) {
+    timeBuffUpdate(self, buff, ETBU_ADD);
+}
+
+void Buffs::timeBuffUpdateDelete(EntityRef self, BuffStack* buff) {
+    timeBuffUpdate(self, buff, ETBU_DEL);
+}