OpenFlow 1.0: rewrite without openflow-1.0.h

The first revision of the header file was copied from the original
distribution tarball intact to use sizeof() instead of adding new
constants on one hand and provide structure definitions for a reference
on the other. But as soon as the structures had a portability issue and
were removed in commit a6c16ed, the remaining fragments of the header
don't justify for a file of its own.

This commit maps all relevant bits of the remaining contents of
openflow-1.0.h to constants in print-openflow-1.0.c (all being specific
to version 1.0 of OpenFlow) and removes the file.
fix license boilerplate in openflow.h

openflow.h in tcpdump doesn't belong to the openflow distribution and
shouldn't be attributed to stanford.edu (probably a copy-and-paste
case). Replace with 2-clause BSD.