tcp_transport: renamed transport related header files to esp_ prefixed to avoid collisions

tcp_transport component used public header files such as 'transport.h', etc. which are too generic and might collide with user or user libraries headers
This change closes #2417

components/tcp_transport/include/esp_transport_utils.h

@@ -0,0 +1,40 @@
+// Copyright 2015-2018 Espressif Systems (Shanghai) PTE LTD
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef _TRANSPORT_UTILS_H_
+#define _TRANSPORT_UTILS_H_
+#include <sys/time.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/**
+ * @brief      Convert milliseconds to timeval struct
+ *
+ * @param[in]  timeout_ms  The timeout milliseconds
+ * @param[out] tv          Timeval struct
+ */
+void transport_utils_ms_to_timeval(int timeout_ms, struct timeval *tv);
+
+
+#define TRANSPORT_MEM_CHECK(TAG, a, action) if (!(a)) {                                                      \
+        ESP_LOGE(TAG,"%s:%d (%s): %s", __FILE__, __LINE__, __FUNCTION__, "Memory exhausted");       \
+        action;                                                                                         \
+        }
+
+#ifdef __cplusplus
+}
+#endif
+#endif /* _TRANSPORT_UTILS_H_ */