Enhanced SDP Python installer to 'http:' protocol in place of
'ftp:' in URL references. This works around a problem I encountered
with outbound 'ftp' being blocked by some corporate firewall (not the
local machine firewall). Using 'http:' in the URL works just as well
for the purposes of this script.
Enhanced SDP Perl installer in the same way, but the SDP Perl is broken
now for unrelated reasons.