Moving the basic Easy game to its own file

Moving this into its own file so I can have a single mazeGame.py file
where users select maze size and difficulty.
Add marking functionality

Player can now "Mark" the current square with a single character.
Updating solvers for new verifiable end-states

Updated the way this thing checks for the end state, because the Maze
class now stores the end location, and can this be compared to the
current location.
Add randomExits, exitLoc, drawGridLocal, etc.

Adding support for building a maze with a randomly placed exit (on the
outside of the maze)
Stores the location of the maze exit on itself so I can check against
that in game code
Updated the drawGrid function so it draws the cell's .string attr for
its center if no other conditions (unvisited, not current location)
apply. This is to support marking functionality.
Added a drawGridLocal function for hardmode. It'll go through and check
the player's current location and construct a 3x3 grid around the player
and draw only that. It's really hacky, but it works for now.
Add mazeGame

Adding mazeGame with user-selected difficulty and size, with marking
functionality. Outputs a report of the player's number of steps and the
final state of the maze (marks n' all).

Checks the player's location against the end location of the maze at
every step, to ensure we're not outside the maze.