Import lwIP contrib rep

... from http://git.savannah.gnu.org/cgit/lwip/lwip-contrib.git/ into contrib/ subdir, STABLE-2_1_0_RELEASE tag
lwIP contrib is now officially frozen
TODO: Fix build

contrib/ports/unix/example_app/Makefile

@@ -0,0 +1,58 @@
+#
+# Copyright (c) 2001, 2002 Swedish Institute of Computer Science.
+# All rights reserved. 
+# 
+# Redistribution and use in source and binary forms, with or without modification, 
+# are permitted provided that the following conditions are met:
+#
+# 1. Redistributions of source code must retain the above copyright notice,
+#    this list of conditions and the following disclaimer.
+# 2. Redistributions in binary form must reproduce the above copyright notice,
+#    this list of conditions and the following disclaimer in the documentation
+#    and/or other materials provided with the distribution.
+# 3. The name of the author may not be used to endorse or promote products
+#    derived from this software without specific prior written permission. 
+#
+# THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED 
+# WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF 
+# MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT 
+# SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, 
+# EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT 
+# OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 
+# INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 
+# CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING 
+# IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY 
+# OF SUCH DAMAGE.
+#
+# This file is part of the lwIP TCP/IP stack.
+# 
+# Author: Adam Dunkels <adam@sics.se>
+#
+
+all compile: example_app makefsdata
+.PHONY: all
+
+include ../Common.mk
+
+CFLAGS+=-I$(CONTRIBDIR)/examples/example_app
+
+TESTFLAGS?=
+CFLAGS+=$(TESTFLAGS)
+
+MAKEFSDATAOBJS=$(notdir $(MAKEFSDATAFILES:.c=.o))
+
+clean:
+	rm -f *.o $(LWIPLIBCOMMON) $(APPLIB) example_app makefsdata *.s .depend* *.core core
+
+depend dep: .depend
+
+include .depend
+
+.depend: $(CONTRIBDIR)/examples/example_app/test.c default_netif.c $(LWIPFILES) $(APPFILES) $(MAKEFSDATAFILES)
+	$(CCDEP) $(CFLAGS) -MM $^ > .depend || rm -f .depend
+
+example_app: .depend $(LWIPLIBCOMMON) $(APPLIB) default_netif.o test.o
+	$(CC) $(CFLAGS) -o example_app test.o default_netif.o -Wl,--start-group $(APPLIB) $(LWIPLIBCOMMON) -Wl,--end-group $(LDFLAGS)
+
+makefsdata: .depend $(MAKEFSDATAOBJS)
+	$(CC) $(CFLAGS) -o makefsdata $(MAKEFSDATAOBJS)