Relicense files for which I am the sole author (as identified by
util/relicense.pl).

Signed-off-by: Michael Brown <mcb30@ipxe.org>

Add FILE_LICENCE declarations to almost all files that make up the
various standard builds of gPXE.

bytes of useless zeroes in the final image.

by PXE and NBI) and UNDI packets (as used by undinet and UNDI).