Add class GameApp

This is the main class handling application lifetime.
Add class GameLogic
Fix Qt objects
Add back button
Add title to the main window
Add Qt example for multipages app
[qt-pages] add Board component
[qt-pages] copy board from qt-board
[qt-pages] fix Main Menu
[qt-pages] add Board to New Game screen
[qt-board] remove unused file
[qt-board] define Board object
[qt-board] move board implementation to Board
[qt-board] add human views for different pages
[qt-board] fix human views
[qt-board] load qml in GameApp
[qt-board] add main menu page
[qt-board] fix human views
[qt-board] show MainMenuView first
[qt-board] remove log on state change