LibCore: Move GIODevice hierarchy from LibGUI to LibCore.

LibCore/CTCPSocket.cpp

@@ -0,0 +1,19 @@
+#include <LibCore/CTCPSocket.h>
+#include <sys/socket.h>
+
+CTCPSocket::CTCPSocket(CObject* parent)
+    : CSocket(CSocket::Type::TCP, parent)
+{
+    int fd = socket(AF_INET, SOCK_STREAM | SOCK_NONBLOCK, 0);
+    if (fd < 0) {
+        set_error(fd);
+    } else {
+        set_fd(fd);
+        set_mode(CIODevice::ReadWrite);
+        set_error(0);
+    }
+}
+
+CTCPSocket::~CTCPSocket()
+{
+}