Show basic store menu functionality

If the person moves a player next to the "door" to a store and inputs
the direction towards this door (w a s d - whichever corresponds to the
relative direction from player -> door), a basic menu pops up on the
side of the screen. This causes the game to enter a second while loop,
such that they are the 'menu' mode and all commands go towards buying
things from the menu (they cannot move)

menu currently has no functionality, will add this later - just shows
the menu and prevents user movement

if the user enters 'q' while in a buy menu, the buy menu goes away and
the town map returns to its original state (buy menu goes away); note
that this 'q' does not end the program - if the player THEN enters q,
after having left the buy menu, the program ends properly
change permissions of performActionInDirection