Port to SFML3

[thypon]

• Migrate sf::VideoMode to use sf::Vector2u for size (width/height merged into .size.x/.size.y)
• Replace sf::Event::KeyPressed/KeyReleased union access with evt.getIfsf::Event::KeyPressed/KeyReleased()
• Add sf::Keyboard::Key:: prefix to all keyboard key enum values
• Replace sf::Style::Fullscreen with sf::State::Fullscreen and add state parameter to window.create()
• Change sf::Image::create() to sf::Image::resize() with Vector2u parameter
• Update collision detection and rect operations to use Vector2f variants
• Update audio system to use new SFML3 streaming and buffer APIs
• Replace deprecated sf::Mouse::getPosition with sf::Mouse::getGlobalPosition

[Quintus]

Whoa, that’s a large step. I will try to take a look next weekend, but at the first glance it actually looks fine. I have not tried to compile it yet, though.

Thank you so far.