Added IoT Socket implementation with FreeRTOS-Plus-TCP
Added IoT Socket implementation with VSocket
Updated IoT Socket implementation with MDK Network:
- added support for Network version 8
- fixed problem with socket operation in server mode
- corrected possible memset overflow
Updated IoT Socket implementation with lwIP:
- corrected iotSocketGetOpt/iotSocketSetOpt timeout options
Added Socket layers:
- VSocket
- FreeRTOS+TCP over Ethernet
- MDK Network over Ethernet
- WiFi