Update glob and follow symlinks when looking for partials

Currently, partials don't follow symbolic links.

A common use case (and one we're using) is registering './bower_components' as a partials dir - which works fine - but then trying to use `bower link` (which creates a symbolic link to a local copy of the component repo) to develop locally between components.
Bah, have a feeling this might just be a horrid hack - was just trying
stuff out and it happened to work in my case. Will take a proper look in
the new year - but maybe this is more like what we'd want:
https://github.com/isaacs/node-glob/issues/142

On Wed, Dec 24, 2014 at 5:48 PM, Eric Ferraiuolo <notifications@github.com>
wrote:

> In lib/express-handlebars.js
> <https://github.com/ericf/express-handlebars/pull/98#discussion-diff-22260888>
> :
>
> > @@ -242,7 +242,7 @@ ExpressHandlebars.prototype._getDir = function (dirPath, options) {
> >      // Optimistically cache dir promise to reduce file system I/O, but remove
> >      // from cache if there was a problem.
> >      dir = cache[dirPath] = new Promise(function (resolve, reject) {
> > -        glob(pattern, {cwd: dirPath}, function (err, dir) {
> > +        glob(pattern, {cwd: dirPath, symlinks: true}, function (err, dir) {
>
> Looking at Glob's options it says:
>
> A cache of known symbolic links. You may pass in a previously generated
> symlinks object to save lstat calls when resolving ** matches.
>
> So I'm not sure how passing a value of true would have any affect on Glob
> and make it follow symlinks. Can you explain more how this changes the
> behavior of Glob?
>
> —
> Reply to this email directly or view it on GitHub
> <https://github.com/ericf/express-handlebars/pull/98/files#r22260888>.
>