Test Fix: latest test now fails when it detects an err object.
Simplify error handling in test callbacks.

The 'done' callback given by jasmine-node fails the spec if its error
parameter is non-null, so no need to manually keep a reference to the
spec object just to call spec.fail().
Update README.md.
Refactor tests. Less boilerplate, more DRY.
Reformat some code.
Small refactoring. Remove some unnecessary lines.
Add pho dependency.
Refactor render(...) function.
Refactor render(...) function (again).
Refactor compile(...) function.
Refactor renderBatch(...) function.
Refactor __result(...) function.
Bug fix: returns correct results when zero markdown files found.

Previous Behavior: pass null results to done callback.
Current Behavior: pass empty results (empty array) to done callback.
Test fix: using path.join for realz. Diffs are comical.
Refactor files(...) function.
Refactor build(...) function.
Whitespace.
Update .gitattributes.
Add pho 0.1.0 dependency.
Use the pho/underscore mixin feature.