Improvements for program

1) Code improved for centering dialog windows on main window of the program in MS Windows OS;
2) Added support for load and use Qt library translation files (tested in MS Windows and Linux based OS);
3) Fixed problem with dot sign in notes' names;
4) Fixed translation on Russian;
5) Added scripts (in directory "dist") for generation an installer program for MS Windows OS.
All tested with Qt 4.8.5.