Unity 2018 and some fixes

Hello I've updated the game so that it now runs on Unity 2018. This means the game should enjoy some optimizations done in the engine and some of the assets used in the game. I've also discovered some horrendously poorly optimized code causing the long loading times at start. The game should now load faster. Some work still remains to be done, so there will be an additional update to further improve this in the near future. The update also fixed two minor bugs: A broken shader in level 4. This shader was not visible and as such it has been removed altogether. A raycasting issue relating to resolution scaling and clicking notes has also been fixed. / Dispersing Minds