Yet another attempt at sorting out room redescribing logic

Tested and working for:
  1: Adventureland
  2: Pirate Adventure (BYTE Magazine)
  3: Secret Mission
  8: Pyramid of Doom
  The Great Blackberry Adventure

The biggest sticking point was the behaviour of the "small nomad"
in "Pyramid of Doom". This is because if a room is automatically
described when the player moves into it and also when its content
changes then the process of the nomad following the player around
causes rooms to be described twice, one with, and once without the
nomad.

Closes-Bug: #9, #10

src/debug.inc

@@ -212,7 +212,7 @@ End Sub
 Sub debug.dump_message(idx%)
   Local s$ = ms$(idx%)
   If s$ = "" Then s$ = "<empty>"
-  debug.println(str.rpad$(Str$(idx%) + ":", 6) + s$)
+  debug.println(str.rpad$(Str$(idx%) + ":", 6) + Chr$(34) + s$ + Chr$(34))
 End Sub
 
 Sub debug.dump_objects(nstr$)