[refactor] Remove the word 'Manager' from most source files/namespaces

ChatManager -> Chat
MissionManager -> Missions
NanoManager -> Nanos
TransportManager -> Transport
ChunkManager -> Chunking
BuddyManager -> Buddies
GroupManager -> Groups
RacingManager -> Racing
ItemManager -> Items

NPCManager and PlayerManager remain.

Note: You can use git log --follow src/file.cpp to trace the history of
a file from before it was renamed.

src/Chunking.hpp

@@ -0,0 +1,47 @@
+#pragma once
+
+#include "CNProtocol.hpp"
+#include "CNStructs.hpp"
+
+#include <utility>
+#include <set>
+#include <map>
+#include <tuple>
+#include <algorithm>
+
+class Chunk {
+public:
+    std::set<CNSocket*> players;
+    std::set<int32_t> NPCs;
+};
+
+enum {
+    INSTANCE_OVERWORLD, // default instance every player starts in
+    INSTANCE_IZ, // these aren't actually used
+    INSTANCE_UNIQUE // these aren't actually used
+};
+
+namespace Chunking {
+    extern std::map<ChunkPos, Chunk*> chunks;
+
+    void updatePlayerChunk(CNSocket* sock, ChunkPos from, ChunkPos to);
+    void updateNPCChunk(int32_t id, ChunkPos from, ChunkPos to);
+
+    void trackPlayer(ChunkPos chunkPos, CNSocket* sock);
+    void trackNPC(ChunkPos chunkPos, int32_t id);
+    void untrackPlayer(ChunkPos chunkPos, CNSocket* sock);
+    void untrackNPC(ChunkPos chunkPos, int32_t id);
+
+    void addPlayerToChunks(std::set<Chunk*> chnks, CNSocket* sock);
+    void addNPCToChunks(std::set<Chunk*> chnks, int32_t id);
+    void removePlayerFromChunks(std::set<Chunk*> chnks, CNSocket* sock);
+    void removeNPCFromChunks(std::set<Chunk*> chnks, int32_t id);
+
+    bool chunkExists(ChunkPos chunk);
+    ChunkPos chunkPosAt(int posX, int posY, uint64_t instanceID);
+    std::set<Chunk*> getViewableChunks(ChunkPos chunkPos);
+
+    bool inPopulatedChunks(std::set<Chunk*>* chnks);
+    void createInstance(uint64_t);
+    void destroyInstanceIfEmpty(uint64_t);
+}