upstream: add a SetEnv directive to ssh_config that allows setting

environment variables for the remote session (subject to the server accepting
them)

refactor SendEnv to remove the arbitrary limit of variable names.

ok markus@

OpenBSD-Commit-ID: cfbb00d9b0e10c1ffff1d83424351fd961d1f2be
diff --git a/misc.h b/misc.h
index daa4abc..837b005 100644
--- a/misc.h
+++ b/misc.h
@@ -1,4 +1,4 @@
-/* $OpenBSD: misc.h,v 1.72 2018/06/06 18:29:18 markus Exp $ */
+/* $OpenBSD: misc.h,v 1.73 2018/06/09 03:01:12 djm Exp $ */
 
 /*
  * Author: Tatu Ylonen <ylo@cs.hut.fi>
@@ -45,6 +45,7 @@
 
 char	*chop(char *);
 char	*strdelim(char **);
+char	*strdelimw(char **);
 int	 set_nonblock(int);
 int	 unset_nonblock(int);
 void	 set_nodelay(int);