bug#700: hideshow.el micro improvements

[Chong Yidong]

> 1. show
>
> xxx {...} yyy {...}
>
> instead of
>
> xxx {...
> }

You patch did not work properly for GNU-style braces.  I've checked in a
fix that works a little better for both cases.

> 2. in the hs-hide-level-recursive skip parenthesis inside comments
> because of they can be unbalanced

Could you give a test recipe that shows this bug?