Bug fix! Frame should not change to play frame.
Bug fix! Fix time step is now using the correct timestep.
Pause event class created.
class TetrisWindow now defined in cpp file.
class TextButton definition moved to cpp file.
Pause and unpause the game is now working.
Highscore is now working.
If a record is ashieved it will be saved as a record.
It is loaded and saved from the file "highscore".
Bug fix! Paused all the time!
Missing "=" now added.