Add colorcoded rendering

CoopSweeper/GameTypes/Field.cs

@@ -16,19 +16,20 @@ namespace CoopSweeper.GameTypes
 
         public FieldState State { get; set; }
 
-        public char ToChar()
+        public DisplayState GetDisplayState()
         {
             switch(State)
             {
-                case FieldState.FLAG: return 'F';
-                case FieldState.NONE: return '◌';
-                case FieldState.QUESTIONMARK: return '?';
+                case FieldState.QUESTIONMARK:
+                case FieldState.NONE:
+                case FieldState.FLAG: 
+                        return (DisplayState)State;
                 case FieldState.REVEALED: 
                     if(ContainsBomb)
-                        return '☼';
-                    return ' ';
+                        return DisplayState.BOMB;
+                    return 0;
             }
-            return 'E';
+            return DisplayState.ERROR;
         }
     }
 }