[PR #1243. Cherry picked with new commit log message. PatR]
Fixes issue where room_discovered was never called for shops
unless #overview was called while inside the shop, fixes#1241.
Issue #1241 reported by mark-mcknight-oncorps.
Triggered by commit e4026d55fb
last December: Lazy evaluation of overview info.
Closes#1243Closes#1241
disperse