Merge branch 'ser'

app/src/main/java/sudoku/Cell.java

@@ -1,5 +1,7 @@
 package sudoku;
 
+import com.fasterxml.jackson.annotation.JsonProperty;
+
 public abstract class Cell {
 
 	protected static int NOSYMBOLE = -1;
@@ -25,8 +27,8 @@ public abstract class Cell {
 		return this.block;
 	}
 
-	// only SudokuFactory should access this
-	void setBlock(Block block) {
+	// only SudokuFactory and SudokuSerializer should access this
+	public void setBlock(Block block) {
 		this.block = block;
 	}