Pull request from entrez: the just-picked-up flag on recently
picked up items was being reset when you stepped on other items
without picking anything else up.
Closes #784
restrict stunning effect to is_xport trap types
lua's garbage collection didn't like the way nethack was trying to use it and
issued a pair of warnings each time the relevant code got run
+items flagged as just-picked-up were unflagged if you stepped on other items
+ without picking anything up
curses: 'msg_window' option wasn't functional for curses unless the binary
also included tty support