Core: Massive refactor in progress.

Things are still progressing. There's building rubble everywhere, but the
scaffold of the refactor is taking place.

* Changed the way the instrument map is structured
* Reworking statistics to be faster, more flexible, and less buggy
* Switched from SequenceExpressions to CallExpressions, letting me gather the
  result of an expression
* Pulled the require-override out of the reporter
* Cleaned up the CLI a little bit
* Added many additional tests focusing on instrument map format, and statistics.
* Updated the reporter to load a pre burned map, giving much more accurate
  statistics. Now files which aren't loaded during testing are still reported.
* Adding an 'it' override to the mocha reporter. This will give much more
  accurate depth calculations.

Impact: Extremely High
Updated reporter.