isaacs/npm — pull request #4353 by mzedayda (2013-12-20 11:11:38+00:00)
Title: add duplicate-sub-deps option flag to npm install + test

```
npm install . --duplicate-sub-deps
```
will install all dependencies even if they are already met on higher levels

Can be useful when folder structure counts.
also makes install process less unpredictable, see #4037