Merge changes to main.

This commit brings in the refactoring and restructuring changes
from IntegrationTesting1 branch to the main branch.
It also includes additional unit tests for 100% coverage.
The rationale behind not creating a PR is that the conflicts were too
huge to be resolved correctly. Thus, a force push to the main branch is
being done.

source/include/FreeRTOS_TCP_Utils.h

@@ -0,0 +1,53 @@
+/*
+ * FreeRTOS+TCP V2.3.4
+ * Copyright (C) 2021 Amazon.com, Inc. or its affiliates.  All Rights Reserved.
+ *
+ * SPDX-License-Identifier: MIT
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy of
+ * this software and associated documentation files (the "Software"), to deal in
+ * the Software without restriction, including without limitation the rights to
+ * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
+ * the Software, and to permit persons to whom the Software is furnished to do so,
+ * subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+ * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
+ * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
+ * IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ *
+ * http://aws.amazon.com/freertos
+ * http://www.FreeRTOS.org
+ */
+
+#ifndef FREERTOS_TCP_UTILS_H
+    #define FREERTOS_TCP_UTILS_H
+
+    #ifdef __cplusplus
+        extern "C" {
+    #endif
+
+
+/*
+ * For logging and debugging: make a string showing the TCP flags.
+ */
+    #if ( ipconfigHAS_DEBUG_PRINTF != 0 )
+        const char * prvTCPFlagMeaning( UBaseType_t xFlags );
+    #endif /* ipconfigHAS_DEBUG_PRINTF != 0 */
+
+/*
+ * Set the initial value for MSS (Maximum Segment Size) to be used.
+ */
+    void prvSocketSetMSS( FreeRTOS_Socket_t * pxSocket );
+
+
+    #ifdef __cplusplus
+        } /* extern "C" */
+    #endif
+
+#endif /* FREERTOS_TCP_UTILS_H */