copyright to 2014
QStringLiteral doesn't exist in qt4
qt4 compatibility for main.cpp
qt4 compatibility AboutDialog
qt4 compatibility in MainWindow
Qt4 backward compatibility in yoMessage
Handling Qt4 backward compatibility in project file
Update ChangeLog
Merge pull request #44 from Alir3z4/feature-#43-qt4-backward-compatibility

Feature #43 qt4 backward compatibility
Fixes #43