[proxy] Auto-symlink /var/run/*.sock in from /var/run/weave/*.sock

Avoids the obscure warning for users

test/650_proxy_env_test.sh

@@ -28,4 +28,10 @@ weave_on $HOST1 stop
 weave_on $HOST1 launch-proxy -H tcp://0.0.0.0:12375 -H unix:///var/run/weave/weave.sock
 check
 
+# Check we can use weave env/config with unix -Hs specified
+weave_on $HOST1 stop
+weave_on $HOST1 launch-proxy -H unix:///var/run/weave/weave.sock
+assert_raises "run_on $HOST1 'eval \$(weave env) ; docker $CMD'"
+assert_raises "run_on $HOST1 'docker \$(weave config) $CMD'"
+
 end_suite