By making them look less like http headers, the hyper mode "tweak"
doesn't interfere.
Enable test 2002 and 2003 in hyper builds (and 1280 which is unrelated
but should be enabled).
Closes#7658
The tftpd test server now logs all received options and thus all TFTP
test cases need to match them exactly.
Extended test 283 to use and verify --tftp-blksize.