heads up: tcpwrappers support going away

[Damien Miller]

Hi,

This is an early warning: OpenSSH will drop tcpwrappers in the next
release. sshd_config has supported the Match keyword for a long time
and it is possible to express more useful conditions (e.g. matching
by user and address) than tcpwrappers allowed.

Removing it reduces the amount of code in the 'hot' pre-authentication
path in sshd and rids us of a dependency.

-d