* Updated vm provisioning scripts to build and install P4Runtime
Also, hardcoded commit ID for each tool to improve reproducibility
of exercises (the P4Runtime API could change in the future).
TODO: there is a permission error at line 114 of user-bootstrap.sh that
needs to be fixed.
* Removed unnecessary compiler flags when bulding PI
* Fixed permission error and updated BMv2 and PI commit IDs
* 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.
* Created new subdirectory for Fall developer day.
* Created vm directory for P4D2_2017_Fall. Fixed emacs permission problem.
* Remove checkout of SIGCOMM branch.
