Print stderr even if script exits with zero exit code

[ahw]

If a hook script prints stuff to stderr but exits "successfully" then VimHooks thinks the whole thing was successful. It'd be nice if it printed stderr anyway whenever it's non-empty because I often have multiple shell commands being run in the same hook and errors can get masked if the last command was successful.

#!/bin/sh

>&2 echo "this is something bad"
echo "this is something good"
false
true # even though stuff was sent to stderr, VimHooks won't report it