Fixed map repr() so it prints dashes instead of None for empty points.

This makes the map much easier to view, and especially to see the points of interest.
Save the locations in a list for the map.

By saving the loaded locations to the grid (for printing and move costs) as well as a list (for easier reference of all locations in a map), we should have the most efficient access for the locations on a map for whatever we need.
Print the location list under the map grid.

The map grid shows the distance between locations, but the symbols mean nothing to the user. Now the list of symbols and locations on the map that prints under the map.
Merge pull request #22 from ChodeGames/better_map_printing

Better map printing