Point out specific file that does failing import

**I'm submitting a feature request**

* **Library Version:**
0.28.0

**Please tell us about your environment:**
* **Operating System:**
any

* **Node Version:**
any

* **NPM Version:**
any

**Current behavior:**
The "requested by" part of the following error during tracing:

`File not found or not accessible: C:/Development/aurelia-cli-static-json/src/inherits_browser.js. Requested by C:\Development\aurelia-cli-static-json\src\app.js`

is not specific enough.

* **What is the expected behavior?**
The actual file that does the failing import to be shown

* **What is the motivation / use case for changing the behavior?**
Makes it easier to find the imports that are causing files not to be found