Merge pull request #3551 from authmillenon/pkg/port/lwip

Makefile.dep

Makefile.pseudomodules

pkg/lwip/Makefile

pkg/lwip/Makefile.include

pkg/lwip/contrib/Makefile

pkg/lwip/contrib/conn/Makefile

pkg/lwip/contrib/conn/ip/Makefile

pkg/lwip/contrib/conn/ip/lwip_conn_ip.c

pkg/lwip/contrib/conn/lwip_conn.c

pkg/lwip/contrib/conn/udp/Makefile

pkg/lwip/contrib/conn/udp/lwip_conn_udp.c

pkg/lwip/contrib/doc.txt

pkg/lwip/contrib/lwip.c

pkg/lwip/contrib/netdev2/Makefile

pkg/lwip/contrib/netdev2/lwip_netdev2.c

pkg/lwip/contrib/sys_arch.c

pkg/lwip/doc.txt

pkg/lwip/include/arch/cc.h

pkg/lwip/include/arch/sys_arch.h

pkg/lwip/include/lwip.h