The Windows host key dialogs now have a `Help' button that should give

appropriate context help, iff the help file is present. (Shame it's prey to
`winhelp-crash'.)

(I've perpetrated a widening of visibility of `hwnd'; the alternative, putting
it into a frontend handle, seemed too likely to cause maintenance trouble if
we don't also _use_ that frontend handle everywhere we now use the global
`hwnd'.)

[originally from svn r5309]

doc/errors.but

@@ -15,6 +15,8 @@ bug (see \k{feedback}) and we will add documentation for it.
 \H{errors-hostkey-absent} \q{The server's host key is not cached in
 the registry}
 
+\cfg{winhelp-topic}{errors.hostkey.absent}
+
 This error message occurs when PuTTY connects to a new SSH server.
 Every server identifies itself by means of a host key; once PuTTY
 knows the host key for a server, it will be able to detect if a
@@ -36,6 +38,8 @@ See \k{gs-hostkey} for more information on host keys.
 
 \H{errors-hostkey-wrong} \q{WARNING - POTENTIAL SECURITY BREACH!}
 
+\cfg{winhelp-topic}{errors.hostkey.changed}
+
 This message, followed by \q{The server's host key does not match
 the one PuTTY has cached in the registry}, means that PuTTY has
 connected to the SSH server before, knows what its host key