FIxes Bug 940499 - add support classifier system

Targeting Socorro 66

This PR extends the processor's classification system to have a 'support' category.  Basically a copy of the infrastructure of the skunk classifiers, this system allows multiple classifications.  Support classification rules follow the  same form as the previously implemented transform rules and skunk classifier rules. The classifications are found in the processed crash like this:

    {
        "classfications": {
            "skunk_works": ...
            "support": [
                { "classification": "bitguard", "classification_data": None, "classification_version": 1.0},
                ...
            ]
        }
    }