improve error reporting, remove duplicate code

include/Common.h

@@ -1,12 +1,15 @@
 #pragma once
 
 #include <atomic>
+#include <cstring>
 #include <deque>
 #include <functional>
 #include <memory>
 #include <mutex>
 #include <sstream>
 
+#include "Compat.h"
+
 #include "TConsole.h"
 
 struct Version {
@@ -133,3 +136,5 @@ void RegisterThread(const std::string str);
 #define Biggest 30000
 std::string Comp(std::string Data);
 std::string DeComp(std::string Compressed);
+
+std::string GetPlatformAgnosticErrorString();

include/Compat.h

@@ -7,6 +7,7 @@
 #include <sys/socket.h>
 #include <termios.h>
 #include <unistd.h>
+#include <errno.h>
 using SOCKET = int;
 using DWORD = unsigned long;
 using PDWORD = unsigned long*;