Crash when state game is re-started [branch fc]

[IohannRabeson]

Reproduce the bug:
Start the game on state game, change the current state to any other state with system.change_state() then change back the state to game.

LLDB backtrace:

• thread README #1: tid = 0x21867, 0x000000010ffd523f, queue = 'com.apple.main-thread', stop reason = EXC_BAD_ACCESS (code=1, address=0x1127d4008)
  frame #0: 0x000000010ffd523f
  -> 0x10ffd523f: movsd (%rdx,%rax), %xmm1
  0x10ffd5244: movsd %xmm1, (%rsi)
  0x10ffd5248: movq %r8, 0x8(%rsi)
  0x10ffd524c: movq 0x3b0(%rcx), %rdx
  (lldb) bt
• thread README #1: tid = 0x21867, 0x000000010ffd523f, queue = 'com.apple.main-thread', stop reason = EXC_BAD_ACCESS (code=1, address=0x1127d4008)
  • frame #0: 0x000000010ffd523f
    frame README #1: 0x00007fff8e78972d GLEngineglDrawArrays_IMM_Exec + 856 frame #2: 0x000000010029c0ff libsfml-graphics.2.2.0.dylibsf::RenderTarget::draw(sf::Vertex const*, unsigned long, sf::PrimitiveType, sf::RenderStates const&) + 463
    frame Create scripts to making redistribuables archives on Linux #3: 0x0000000100055c70 octodyssey.appTransitionManager::draw(this=0x0000000100974a00, render=0x000000010100c0c8, states=RenderStates at 0x00007fff5fbff510) const + 80 at TransitionManager.cpp:384 frame #4: 0x000000010029bf29 libsfml-graphics.2.2.0.dylibsf::RenderTarget::draw(sf::Drawable const&, sf::RenderStates const&) + 41
    frame Added cppcheck to travis and refactored .travis.yml #5: 0x0000000100051d9a octodyssey.appMapManager::draw(this=0x0000000100974958, render=0x000000010100c0c8, states=RenderStates at 0x00007fff5fbff5e0) const + 90 at MapManager.cpp:56 frame #6: 0x000000010029bf29 libsfml-graphics.2.2.0.dylibsf::RenderTarget::draw(sf::Drawable const&, sf::RenderStates const&) + 41
    frame Makefile updated #7: 0x000000010003b638 octodyssey.appStateGame::draw(this=0x0000000100974950, render=0x000000010100c0c8) const + 72 at StateGame.cpp:44 frame #8: 0x000000010007f7bd octodyssey.appocto::StateManager::draw(this=0x000000010100c010, render=0x000000010100c0c8) const + 93 at StateManager.cpp:248
    frame Integration of all stuffs #9: 0x0000000100099297 octodyssey.appocto::ApplicationImp::drawAll(this=0x000000010100c000) + 119 at Application.cpp:246 frame #10: 0x00000001000991b7 octodyssey.appocto::ApplicationImp::run(this=0x000000010100c000) + 343 at Application.cpp:270
    frame Makefile #11: 0x0000000100095410 octodyssey.appocto::Application::run(stateKey=0x00007fff5fbff978) + 112 at Application.cpp:339 frame #12: 0x00000001000657f5 octodyssey.appmain(argc=1, argv=0x00007fff5fbffb10) + 821 at main.cpp:56
    frame Added sprite sheet support #13: 0x00007fff8dc465c9 libdyld.dylib`start + 1