MODIFIED - Updated stack-trace module

MODIFIED - Updated stack-trace module to latest version (v0.0.6)
MODIFIED - Properly logs uncaugh error

MODIFIED - Properly logs uncaugh error that are not an instance of Error
Make development and test default dev environments

It's uncommon to want exceptions to go to Airbrake's servers in development mode and during test runs.
Conflicts:
	lib/airbrake.js
Add accept header for compatiblity with errbit.

Otherwise Errbit responds with 406 Not Acceptable.