testSprite is the id of the sprite to test
for collisions.
If the forSprite
version of this command is used then it just tests for collisions
between testSprite and forSprite.
If the fromSprite
to toSprite version is used then it tests for collisions
between testSprite and all the sprites between fromSprite
and toSprite (inclusive).
sprite is the id of the sprite that
testSprite has collided with. If the sprite has not collided
with anything else then -1 is returned.
Note: it is not possible for a sprite
to collide with itself.