first_kex_packet_follows working, needs tidying

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branch : kexguess
Add kexguess2 behaviour

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branch : kexguess
Get rid of client/server specific buf_match_algo, use single
function with a couple of if statements instead

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branch : kexguess
merge

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branch : kexguess
merge from head roundtrip changes

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branch : kexguess
Fix segfault when /dev/urandom isn't writable
merge
fix tabs
add IUTF8
Add sentinel attribute

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branch : kexguess
Don't usually need to recalculate dh_e for the repeated kexdh_init packet

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branch : kexguess
Put some #ifdef options around first-follows options in case they
need to be disabled

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branch : kexguess
merge kexguess branch
merge