[refactor] Move files to core/ and servers/ subdirectories

CNProtocol, CNShared, CNStructs and Defines are now in core/.
CNLoginServer, CNShardServer and Monitor are now in servers/.

core/Core.hpp wraps all the core headers except for CNShared.hpp.

Defines.cpp has been renamed to Packets.cpp, and so has its
corresponding namespace, but not the header file. This is in preparation
for upcoming changes.

src/core/CNStructs.hpp

@@ -0,0 +1,59 @@
+/*
+ * CNStructs.hpp - defines some basic structs & useful methods for packets used by FusionFall based on the version defined
+ */
+
+#pragma once
+
+#ifdef _MSC_VER
+    // codecvt_* is deprecated in C++17 and MSVC will throw an annoying warning because of that.
+    // Defining this before anything else to silence it.
+    #define _SILENCE_CXX17_CODECVT_HEADER_DEPRECATION_WARNING
+#endif
+
+#include <iostream>
+#include <stdio.h>
+#include <stdint.h>
+#ifndef _MSC_VER
+    #include <sys/time.h>
+#else
+// Can't use this in MSVC.
+    #include <time.h>
+#endif
+#include <cstring>
+#include <string>
+#include <locale>
+#include <codecvt>
+
+// yes this is ugly, but this is needed to zero out the memory so we don't have random stackdata in our structs.
+#define INITSTRUCT(T, x) T x; \
+    memset(&x, 0, sizeof(T));
+
+// macros to extract fields from instanceIDs
+#define MAPNUM(x) ((x) & 0xffffffff)
+#define PLAYERID(x) ((x) >> 32)
+
+// typedef for chunk position tuple
+typedef std::tuple<int, int, uint64_t> ChunkPos;
+
+// TODO: rewrite U16toU8 & U8toU16 to not use codecvt
+
+std::string U16toU8(char16_t* src);
+size_t U8toU16(std::string src, char16_t* des, size_t max); // returns number of char16_t that was written at des
+time_t getTime();
+time_t getTimestamp();
+void terminate(int);
+
+// The PROTOCOL_VERSION definition is defined by the build system.
+#if !defined(PROTOCOL_VERSION)
+    #include "structs/0104.hpp"
+#elif PROTOCOL_VERSION == 728
+    #include "structs/0728.hpp"
+#elif PROTOCOL_VERSION == 104
+    #include "structs/0104.hpp"
+#elif PROTOCOL_VERSION == 1013
+    #include "structs/1013.hpp"
+#else
+    #error Invalid PROTOCOL_VERSION
+#endif
+
+sSYSTEMTIME timeStampToStruct(uint64_t time);