add fake idle animations to avoid endless muzzle sprites

fixes #3852
removed unused tileset builder templates
made more cliffs unpassable to avoid glitches

fixes #3701
don't explode when not in world

fixes #3895
StyleCop cleanup
also don't leave a husk somewhere when loaded as cargo
Merge pull request #3908 from Mailaender/explode-in-world

Fixed cargos exploding where they were loaded
Merge pull request #3907 from Mailaender/passable-cliffs

Fixed passable cliffs on Arrakis
Merge pull request #3906 from Mailaender/d2k-idle-infantry

Fixed D2k infantry stopping during a firing animation with muzzle flash
Merge pull request #3905 from Mailaender/splashscreens

Removed Loadscreen redundancy
remove redundant install and download logic