Update mocha version.
Add 'lint' and 'coverage' target.

- Use jshint for linting. Include local code, exclude imported code.
- Use the coverage target as an alias for the Makefile functionality.
Show more jshint errors.
Fix lint issues.

- Fix semicolon issues.
- Move out of scope vars outside of try blocks.
- Fix array push() method typo.
- Wrap 'use strict' code in a function.