Don't show coverage report when there's no data

Fixes #127
Provide real error messaging for functional test failures

Fixes #178.
[WIP] Normalize console reporter error display
Source address parsing bugfix
Use my modified istanbul as the dependency
[WIP] Stack traces are normalized and corrected

Stack traces are mostly normalized between different browsers. Stack
trace lines are updated based on instrumentation source map data if
available.
[WIP] Cleanup, fix to line:col parsing
[WIP] Improve cross-browser support

Every browser outputs stack data differently. Aside from basic format
differences, IE, Chrome, Firefox, and Safari each output different
column values for the same exception.
  - IE uses the column at the start of the statement that caused the
	exception.
  - Chrome uses the column at the start of the term (e.g., variable
	name) that caused the exception.
  - Safari uses the column just after the term that caused the
	exception.
  - Firefox doesn't output column numbers, only line numbers.
[WIP] Support for standard source maps, cleanup
Cleanup