- Moved constructors, destructors and some methods into implementation file

Signed-off-by: Jan Nemecek <Nemecek.Jan@seznam.cz>
- Moved destructor to implementation file

Signed-off-by: Jan Nemecek <Nemecek.Jan@seznam.cz>
- Replaced 0 with nullptr

Signed-off-by: Jan Nemecek <Nemecek.Jan@seznam.cz>
- Moved old_main() to try-catch block

Signed-off-by: Jan Nemecek <Nemecek.Jan@seznam.cz>