collisions with openCv blobs

[david-sullivan]

It would be great to have an example that showed how to have ofxBox2d interact with ofxOpenCv. Most of the examples that are out there are old and no longer work.
I tried my hand at it, and put it here:
https://github.com/david-sullivan/box2dCamera

Maybe not the best code, but it works (for the most part).

thanks for the addon!