[WIP] Make nested braces and brace ranges work

This pull request should resolve editorconfig/editorconfig#81

The main problem is that nested expansion of `*` and other things don't work inside braces.
The c version treats this as two cases '-' and ']'. I'm wondering if this is elif block is where the error lies. I recommend treating as separate cases to see if you can get it working as analogous to the c version.