Added layer2 SOCK_RAW example code and stubs

test/layer2.cpp

@@ -0,0 +1,33 @@
+// This file is built with libzt.a via `make tests`
+
+#include <unistd.h>
+#include <stdio.h>
+#include <sys/socket.h>
+#include <netinet/ip.h>
+#include <netinet/udp.h>
+
+#include "libzt.h"
+
+int main(int argc , char *argv[])
+{
+	if(argc < 3) {
+        fprintf(stderr, "usage: layer2 <zt_home_dir> <nwid>\n");
+        return 1;
+    }
+
+	printf("Starting libzt...\n");
+	zts_simple_start(argv[1], argv[2]);
+	char device_id[11];
+	zts_get_device_id(device_id);
+	printf("Complete. I am %s\n", device_id);
+
+	// layer2 example code
+	int rawsock;
+	if((rawsock = zts_socket(AF_INET, SOCK_RAW, IPPROTO_UDP)) < 0)
+	{
+		printf("There was a problem creating the raw socket\n");
+		return -1;
+	}
+	printf("Created raw socket (%d)\n", rawsock);
+	return 0;
+}