Shop rank caps based on the code

Useful shop rank caps as of 1.90+:

    Number of pages:

    Blacksmith   -  840
    Blackmarket   -  210
    Random shops - 60,000 fame
    Remaining    - 120

    Amount of an item:

    Bakery       - 89
    trade good   - no limit?  Seems to go up ~1 stock per 75 ranks.  inv(INV_ITEM_NUM, ci) = inv(INV_ITEM_NUM, ci) * (100 + shoprank) / 75 + 1


    Quality upgrade:   (after random gen)

    blackmarket  - 4000 miracle chance
    blacksmith   - 1000 great   chance

    Item selection::

    Higher rank does something to the filter list when choosing items. Dunno what..