Reset sprinting if the player is not set sprinting.

Only give the sprintinggrace time concerning the food level.
Should fix more sprintback issues, potentially.
More cleanup for survivalfly.

Move the after-failure permission-, velocity- and 
extra-buffer-checks into an extra method.

Move special checks like web/liquid to extra methods.

Alter checking order slightly.

Other cleanups (comments, declaration order, grouping).

Shuffle methods.

Finished? No.