shiny object probabilities

shiny object probabilities

The wishing code uses 'oc_prob + 1' so that probability 0 (never
random) objects are eligible to be selected if their name matches
a wish; collecting 'shiny' objects shouldn't do that.  (No effect
on play since there aren't any shiny objects with 0% random chance.)

rn2() takes int, and total oc_prob for entire objects[] array is
15000, so don't accumulate the target probability in a long.