API: new method setupWhereFailed

Sometimes the small things are the ones that make the greatest difference.

So with python-opsi comes a new method setupWhereFailed that takes an product ID as parameter and then will set that product to setup on all clients where that product has failed as action result.

I used this during some development tests and this made things very straight forward.

Here is how you can use it through opsi-admin with the product testproduct:

opsi-admin -d method setupWhereFailed testproduct