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

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

Replace MD5 implementation with one which is around 20% smaller.  This
implementation has been verified using the existing MD5 self-tests.

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

Access to the gpxe.org and etherboot.org domains and associated
resources has been revoked by the registrant of the domain.  Work
around this problem by renaming project from gPXE to iPXE, and
updating URLs to match.

Also update README, LOG and COPYRIGHTS to remove obsolete information.

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.

The various types of cryptographic algorithm are fundamentally
different, and it was probably a mistake to try to handle them via a
single common type.

pubkey_algorithm is a placeholder type for now.

code, rather than going through the digest layer.

Removed a spurious line of constants.