Moved loading of Hirb after Wirb, so Wirb doesn't override it.

To fix the Wirb overriding bug that was reported: https://github.com/wireframe/rails-console-tweaks/issues/1

Now you can use both Wirb and Hirb together.

Tested and confirmed that it works.

It will default to Hirb, but if you use Hirb.disable, the Wirb output will be shown, fully colorized.