This patch adds copyright information for the Icarus generated UDPs
(lesser GPL version 2.1). It also prints a note to let the user know
that this copyrighted code is being included in the output file. They
can then remove the primitives if needed. These are likely only
needed when the output is from synthesis. At the moment we only have
a positive edge D-FF. In the future a negative edge FF and D latches
will also be needed.
Cary R