Rename item-subsystem methods (refactor step 5, items)

getItem→promptPackItem now returns (obj, ok) instead of a nil-signaling
pointer; invName→inventoryName; doPot→applyPotionFuse. C breadcrumbs
kept. Behavior unchanged; suite green.

game/things.go

@@ -9,7 +9,7 @@ import (
 
 // invName returns the name of something as it would appear in an inventory
 // (things.c inv_name).
-func (g *RogueGame) invName(obj *Object, drop bool) string {
+func (g *RogueGame) inventoryName(obj *Object, drop bool) string {
 	var pb strings.Builder
 
 	which := obj.Which
@@ -142,8 +142,8 @@ func (g *RogueGame) dropIt() {
 		return
 	}
 
-	obj := g.getItem("drop", KindNone)
-	if obj == nil {
+	obj, ok := g.promptPackItem("drop", KindNone)
+	if !ok {
 		return
 	}
 
@@ -162,7 +162,7 @@ func (g *RogueGame) dropIt() {
 		g.HasAmulet = false
 	}
 
-	g.msg("dropped %s", g.invName(obj, true))
+	g.msg("dropped %s", g.inventoryName(obj, true))
 }
 
 // dropCheck does special checks for dropping or unwielding|unwearing|
@@ -392,7 +392,7 @@ func (g *RogueGame) printDisc(typ byte) {
 		if info[order[i]].Know || info[order[i]].Guess != "" {
 			obj.Kind = objectKindForGlyph(typ)
 			obj.Which = order[i]
-			g.addLine("%s", g.invName(&obj, false))
+			g.addLine("%s", g.inventoryName(&obj, false))
 
 			numFound++
 		}