Library prepared for future use of new versions od FreeRTOS

Library prepared for future use of new versions od FreeRTOS

lwip has been modified to be compatible with the newest FreeRTOS without
warnings, so the library has to be also slightly modified to reflect the changes.

Macro for data type casting of the task name for xTaskCreate function added,
as this function has the name parameter with different data type for newer
FreeRTOS version.

This commit refs: #1021