[PATCH 5 of 8] import-checker: skip site-packages for virtualenv

[Yuya Nishihara]

On Thu, 31 Mar 2016 11:20:05 -0400, timeless wrote:
> > pygments was being treated as a stdlib...  
> 
> Yuya Nishihara <yuya at tcha.org> wrote:
> > If I understand it, pygments should be treated as a stdlib. stdlib_modules is
> > used to sort out system-installed modules from our modules.  
> 
> so, isort has 3 categories: stdlib, other, local
> 
> If what we're trying to capture is "modules that are part of
> mercurial" vs "modules that are not part of mercurial", we should
> rename the concept to "non_mercurial_modules" or "external_modules".
> 
> Personally, I think I favor isort's approach and would suggest we
> probably want to sort into three categories instead of two categories.

Or just checks if a module is ours, i.e. hgext.* or mercurial.*. I think it
should be possible if we can get rid of relative imports.