added char attributes, enemies, combat

I used the strategy/movement system for NPCs from Beast and added
in some of my own mechanics for melee and projectile combat. A leveling
system has also been established which modifies damage as the player
levels up. Next order of business is level design, monster spawning, and
game progression.

map.py

@@ -0,0 +1,61 @@
+from retro.game import Game
+from random import sample
+from player import Player
+from wall import Wall
+from random import randint
+
+def board_edges(board_size):
+    x,y = board_size
+    positions = []
+    top = [(i,0) for i in range(x)]
+    bottom = [(i,y-1) for i in range(x)]
+    left = [(0,j) for j in range(1,y-1)]
+    right = [(x-1,j) for j in range(1,y-1)]
+    return top + bottom + left + right
+
+def inner_board(board_size):
+    x,y = board_size
+    positions = []
+    for i in range(1,x-1):
+        for j in range(1,y-1):
+            positions.append((i,j))
+    return positions
+
+def random_empty_position(game):
+    """Returns a random empty position.
+    """
+    agents_by_position = game.get_agents_by_position()
+    while True:
+        x, y = game.board_size
+        i = randint(1, x-2)
+        j = randint(1, y-2)
+        if not agents_by_position[(i,j)]:
+            return (i,j)
+
+def level_one(board_size):
+    x,y = board_size
+    positions = []
+    for i in range(1,x-1):
+        for j in range(1,y//4):
+            if i <= x // 4 or i >= x - (x // 4):
+                positions.append((i,j))
+    for i in range(1,x//4):
+        for j in range((y - (y // 4)), y-1):
+            positions.append((i,j))
+
+    # for i in range(1,x-1):
+    #     for j in range(1,y-1):
+    #         if i >=4 and i <= 7 or i >= 13 and i <= 16:
+    #             if j >= 4 and j <= 7 or j >= 13 and j <= 16:
+    #                 positions.append((i,j))
+    return positions
+
+def level_two(board_size):
+    x,y = board_size
+    positions = []
+    for i in range(1,x-1):
+        for j in range(1,y-1):
+            if i >=4 and i <= 7 or i >= 13 and i <= 16:
+                if j >= 4 and j <= 7 or j >= 13 and j <= 16:
+                    positions.append((i,j))
+    return positions