the recent commits converted the tabs to 4 spaces, which matched the
initial indent size. Other commits converted the tabs to 8 spaces, this
didn't match.
All the code has been converted to 4 space indents. No changes to line
lengths or actual code was performed. This is in preperation to my up
coming non-blocking work so my commits should only be code changes and
line lengths in the code I am working on.
key_len should not have been in KEX_METHOD,
it's dependent on MAC method, not KEX method.
This is why the MD5 MACs were borked initially,
md5 has a key_len of 16, not 20.
