Yeah, hideous, but this allows us to be loaded before Mocha, which is handy.
function injectMocha(Mocha) {
    _injectPrototype(Console, Mocha.reporters.Base.prototype);
    _injectPrototype(HTML, Mocha.reporters.HTML.prototype);
    // Mocha doesn't expose its `EventEmitter` shim directly, so:
    _injectPrototype(MultiReporter, Object.getPrototypeOf(Mocha.Runner.prototype));
}