Change camera to be track target node, instead of being its' child

[kikonen]

From #57

Would be better for camera having different tracking logic than being strict child node would be better, since this child node approach is far too strict, and causes akward camera movement.

Thus camera component need to have

• target node
• tracking mode (i.e. how tightly, and such it follows target)

=> This should reduce jerky movement from camera

[kikonen]

Using gcpp as source for this to implement different camera modes to track "player"

[kikonen]

DONE

• camera is now back being component of node instead of child node of it
  • allows somewhat better camera control