Update v1.5.0 - new look!

This time you might notice that JICE looks a bit different from before! This patch includes major visual changes such as:

• New shader! JICE looks even more cartoony now, as it was meant to be
• Multiple models (science-themed walls and smiley cubes) were remade
• New clouds that better suit the new look
• Minor level design changes, some of which are more noticeable than others.

Overall, this is not by any means a final look for the game and is subject to change on many iterations later on, but is still a huge step towards what I am aiming at. Any feedback about the changes is greatly appreciated!