refactor: move classes

app/src/main/java/sudoku/Main.java

@@ -4,7 +4,7 @@
 package sudoku;
 
 import gui.RenderableMultidoku;
-import gui.Symbols;
+import gui.constants.Symbols;
 import sudoku.io.ConsoleInterface;
 import sudoku.io.SudokuPrinter;
 import sudoku.io.SudokuSerializer;

app/src/main/java/sudoku/io/ConsoleInterface.java

@@ -1,7 +1,7 @@
 package sudoku.io;
 
 import gui.RenderableMultidoku;
-import gui.Symbols;
+import gui.constants.Symbols;
 import sudoku.constraint.*;
 import sudoku.solver.*;
 import sudoku.structure.*;

app/src/main/java/sudoku/io/SudokuPrinter.java

@@ -1,7 +1,7 @@
 package sudoku.io;
 
 import gui.RenderableMultidoku;
-import gui.Symbols;
+import gui.constants.Symbols;
 import sudoku.structure.Cell;
 import sudoku.structure.MultiDoku;
 import sudoku.structure.Sudoku;

app/src/main/java/sudoku/solver/HumanSolver.java

@@ -4,7 +4,7 @@ import java.util.List;
 import java.util.concurrent.CancellationException;
 import java.util.logging.Level;
 
-import gui.Symbols;
+import gui.constants.Symbols;
 import sudoku.io.SudokuPrinter;
 import sudoku.structure.Cell;
 import sudoku.structure.MultiDoku;

app/src/main/java/sudoku/solver/MixedSolver.java

@@ -5,7 +5,7 @@ import java.util.Random;
 import java.util.concurrent.CancellationException;
 import java.util.logging.Level;
 
-import gui.Symbols;
+import gui.constants.Symbols;
 import sudoku.io.SudokuPrinter;
 import sudoku.structure.Cell;
 import sudoku.structure.MultiDoku;

app/src/main/java/sudoku/solver/RandomSolver.java

@@ -5,7 +5,7 @@ import java.util.Random;
 import java.util.concurrent.CancellationException;
 import java.util.logging.Level;
 
-import gui.Symbols;
+import gui.constants.Symbols;
 import sudoku.io.SudokuPrinter;
 import sudoku.structure.Cell;
 import sudoku.structure.MultiDoku;