Basic Encapsulation Example (#64)

* Adding initial implementation of basic_encap example

* Updated basic_encap example to count the number of valid packets

* Updated basic_encap example to put encapsulation layer after Ethernet
header.

* Added solution file for basic_encap example

* Changed the name of the basic_encap example to basic_tunnel and called
the new header myTunnel. Also changed the myTunnel field names slightly.

P4D2_2017_Fall/exercises/basic_tunnel/run.sh

@@ -0,0 +1,5 @@
+P4APPRUNNER=../../utils/p4apprunner.py
+mkdir -p build
+tar -czf build/p4app.tgz * --exclude='build'
+#cd build
+sudo python $P4APPRUNNER p4app.tgz --build-dir ./build