Demos big update

-Added some more math functions
-fixed many memory leaks
-added AABB and BVHTree support to collision.d
 *BVHTree has only incrementally adding entities implemented by now (and bad BottomUp algorithm)
 *ECS Systems use two trees, one for static and one for dynamic entities, dynamic BVH is builded every frame from scratch by now
-BrickBreaker now uses BVHTree to collision detection
 *balls only use tree for checks (they aren't adding to tree)
-fixed bug leading to crash

demos/source/app.d

@@ -117,12 +117,12 @@ struct Launcher
         gui_manager.clear();
         //launcher.ent
 
-        if(this.demo.deinitialize)this.demo.deinitialize();
-
         manager.begin();
         manager.update("clean");
         manager.end();
 
+        if(this.demo.deinitialize)this.demo.deinitialize();
+
         foreach(ref system; manager.systems)
         {
             if(system.id != CountSystem.system_id && system.id != CleanSystem.system_id)system.disable();
@@ -946,12 +946,19 @@ void mainLoop(void* arg)
 
 void quit()
 {
+    import game_core.rendering : TexCoordsManager;
     launcher.gui_manager.clear();
     Mallocator.dispose(launcher.gui_manager);
 
+    if(launcher.demo.deinitialize)launcher.demo.deinitialize();
+
     launcher.manager.destroy();
     launcher.manager = null;
 
+    TexCoordsManager.destroy();
+
+    SDL_Quit();
+
     version(WebAssembly)emscripten_cancel_main_loop();
 }
 
@@ -1060,10 +1067,11 @@ int app_main(int argc, char** argv)
         }
     }
     
-    ImFontConfig* config = ImFontConfig_ImFontConfig();
+    //ImFontConfig* config = ImFontConfig_ImFontConfig();
     ImGuiIO* io = igGetIO();
     const ushort* font_ranges = ImFontAtlas_GetGlyphRangesDefault(io.Fonts);
-    ImFontAtlas_AddFontFromFileTTF(io.Fonts,"assets/fonts/Ruda-Bold.ttf", 15.0f, config, font_ranges);
+    ImFontAtlas_AddFontFromFileTTF(io.Fonts,"assets/fonts/Ruda-Bold.ttf", 15.0f, null, font_ranges);
+    //ImFontConfig_destroy(config);
 
     setStyle(3);
 
@@ -1139,9 +1147,6 @@ int app_main(int argc, char** argv)
         }
     }
 
-    TexCoordsManager.destroy();
-    EntityManager.destroy();
-
     return 0;
 }