All changes made for 10th part of tutorial

voxel_engine.cpp - changed structure, added character controls, physics
almost all files are modified (including shaders)
+ new source directory - physics

src/physics/Hitbox.cpp

@@ -0,0 +1,4 @@
+#include "Hitbox.h"
+
+Hitbox::Hitbox(vec3 position, vec3 halfsize) : position(position), halfsize(halfsize), velocity(0.0f,0.0f,0.0f) {
+}