Added 4 more simulations

Content added:

Explosion4 (64x64)  - big chunky explosion suitable for many purposes

Flame2 (16x16) - small fire, great for torches or lanterns

Flame3 (64x64 & 16x16) -  sparkling fire, 16x16 version can be used in sparklers or fire spells and 64x64 version can be used in big wildfires

also added CrazyOverlay1, this is test asset and idk should i keep it there or not, but you can play with it, it will be great for space or sci-fi stuff