Split collision detection into snake collision and wall collision

[clemens-tolboom]

Depends on #275

As found in #275 we should split the detection into two parts. That way we could use the scheduler for two separate task which can be toggles on/off.

This way we or our users can create snakes colliding into walls or change collision into snake behavior without missing the wall.

[ermiyaeskandary]

create snakes colliding into walls

Magnificent with the movetoxy ! We could quickly get the bot to a long length and then test bots head to head or .... !
The skies the limit...
But it may be considered by cheating as some - I classify it as using resources at hand for educational purposes ;)

[ChadSki]

Split collision detection into snake collision and wall collision

Why?

That way we could use the scheduler for two separate task which can be toggles on/off.

Why would you ever want to collide into other snakes or the wall?

This sounds like over-engineering. Your scheduler is interesting but be wary of golden hammer syndrome (if all you have is a hammer everything looks like a nail).