v0.50.0-beta.4

Changes

• 66f9416: Add an option to enable TCP_NODELAY (#435) (Patryk Wychowaniec)
• c9baadf: DH GEX support (#440) - diffie-hellman-group-exchange-sha256 KEX is now on the default kex list. To take advantage of dynamic DH groups, pre-generate some safe primes and implement dynamic group lookup in the server::Handler::lookup_dh_gex_group method - see this method's docs for more info.

Fixes

• 290bdbe: fixed unwrap panic in pageant (Eugene)