Verbose warning option?

__Is your feature request related to a problem? Please describe.__

I've been trying to debug some issues on my app to get it compatible with IE 11. In the process, I'm encountering a lot of warnings (only in IE) e.g. `Warning [JSS] SyntaxError`, `Warning: [JSS] Rule is not linked. Missing sheet option "link: true".`. I'm sure there's a valid reason for the warnings, but I'm at a loss as to where they are being triggered from or what the exact problems are, because the above warnings are the only information I have.

__Describe the solution you'd like__
Ideally, I would like to at least have the option of seeing the full error stack when warnings are encountered by jss, so I can more easily identify what is causing the issues I'm running into. I'm not sure if such a behavior already exists, but from my investigation so far I have not found any.

__Are you willing to implement it?__
*Yes*

No files or tests are named. Start by searching the JSS source for the reported warning strings, then trace how warnings are emitted in IE 11. Done means users can opt into full error stacks for JSS warnings without changing the default warning behavior.

Written by the indexing model from the issue text.