Added ping support

Signed-off-by: J. German Rivera <German.Rivera@freescale.com>
Fixed bug in rtos_k_thread_abort()

Signed-off-by: J. German Rivera <German.Rivera@freescale.com>
Committed change in src/Networking/lwip submodule

Signed-off-by: J. German Rivera <German.Rivera@freescale.com>