Allow importing product.py in places where you won't have a .buildstamp.
    
    If you're running anaconda through some external testing system, you're not
    going to have a .buildstamp file.  However, the defaults dict for the
    ConfigParser object doesn't allow for putting those defaults into a section
    so all the later lookups will fail due to lack of a Main.  Moving to a big
    block of .set calls fixes this up.