Fixes issue in which git version number is not displayed on startup
when iPXE is built through rom-o-matic.

Remove special characters from filename generated by rom-o-matic (so
that you get "ipxe-1.0.0+c3b4-undionly.kkpxe" instead of
"ipxe-1.0.0+ (c3b4)-undionly.kkpxe")

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

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resources has been revoked by the registrant of the domain.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>