Fixed flag mine count exploit

Player could check if a tile was a mine by flagging a tile and seeing if
the remaining mine count changes or not

index.html

@@ -253,7 +253,13 @@
 				}
 
 				function updateMinesLeft() {
-					$('#mines').text("Mines left: " + $('.mine:not(.revealed):not(.flagged)').length);
+					//unflagged mines - revealed mines - flagged not-mines
+					$('#mines').text(
+						"Mines left: " 
+				      + ($('.mine:not(.flagged)').length
+				      -  $('.mine.revealed').length
+				      -  $('li:not(.mine).flagged').length)
+			      	);
 				}
 
 				$.fn.rowScore = function() {