Remove Coalmine from Error/Exception Handling

The service has gone away, it's just a domain placeholder now.

https://www.getcoalmine.com/ - No server there anymore.
http://www.getcoalmine.com/  - Redirects to http://ww2.getcoalmine.com/ which is a domain placeholder.
Merge pull request #77 from jmhobbs/patch-1

Remove Coalmine from Error/Exception Handling