more empty class structs; introduced a lessSIGABRT error when destructing sf::Window

0  0x00007ffff68a8037 in raise () from /lib/x86_64-linux-gnu/libc.so.6
1  0x00007ffff68ab698 in abort () from /lib/x86_64-linux-gnu/libc.so.6
2  0x00007ffff68e55ab in ?? () from /lib/x86_64-linux-gnu/libc.so.6
3  0x00007ffff68f1a46 in ?? () from /lib/x86_64-linux-gnu/libc.so.6
4  0x00007ffff17d34fb in ?? () from /usr/lib/fglrx/dri/fglrx_dri.so
5  0x00007ffff17c22c0 in ?? () from /usr/lib/fglrx/dri/fglrx_dri.so
6  0x00007ffff0a8bc6f in ?? () from /usr/lib/fglrx/dri/fglrx_dri.so
7  0x00007ffff1797443 in ?? () from /usr/lib/fglrx/dri/fglrx_dri.so
8  0x00007ffff1799f3d in ?? () from /usr/lib/fglrx/dri/fglrx_dri.so
9  0x00007ffff17ad69f in ?? () from /usr/lib/fglrx/dri/fglrx_dri.so
10 0x00007ffff2327bd6 in ?? () from /usr/lib/fglrx/dri/fglrx_dri.so
11 0x00007ffff5d6032e in ?? () from /usr/lib/fglrx/libGL.so.1
12 0x00007ffff5d6061b in glXDestroyContext () from /usr/lib/fglrx/libGL.so.1
13 0x00007ffff77791a1 in sf::priv::GlxContext::~GlxContext() () from /usr/local/lib/libsfml-window.so.2
14 0x00007ffff7776ad3 in sf::Window::close() () from /usr/local/lib/libsfml-window.so.2
15 0x0000000000402262 in Game::loop (this=0x7fffffffdd50)
    at /home/nehmulos/workspace/knightsgame/game/game.cpp:26
16 0x000000000040277f in main (argc=1, argv=0x7fffffffe048)
    at /home/nehmulos/workspace/knightsgame/game/main.cpp:18