Completed airflower powerup abilities.

Completed airflower powerup abilities.
Airflower is meant to be a powerup geared to speed runs and sky levels.  It makes Tux light on his feet, with a passive ability of faster max run speed and greater attainable jump height.
In addition, airflower has an active ability which allows Tux to glide for a short period of time after jumping.  The duration that Tux can glide increases with additional airflower powerups.  To glide, the user only needs to hold the jump key while falling.  Every time the player jumps they may glide for a set amount of time which is reset upon Tux touching the ground.
Tux sprites still need to be done, and it may be worth considering replacing the backflip with a launching jump when Tux has this powerup.  Of course tweaks to the values used will also likely be needed.