Scroll changes

[takkaria]

• Merge DetTreasure? + DetObjects?, extend over whole level
• Scroll of Deep Descent that sets your recall depth to 3-5dlevs deeper than it was and invokes the WoR effect

BANISHMENT

It seems kind of odd that, once at a depth where either can appear, scrolls of Banishment and of Mass Banishment are equally likely.

Check if they used to have the same rarities; adjust accordingly.

ALLOCATION

Scrolls that are redundant with staves/rods could fade in the depths, ~10 levels after the rods start appearing.

[takkaria]

Done in r907.