v49 Jetpacks

Reverts the changes made to the jetpack in the v50 update:

• Battery life increased from 50s to 60s (Configurable)
• Deceleration increased from 50/s to 75/s
• Drastically decreased turning multiplier from 50x to 1x
• Unfixed the bug that caused "overheat explosions" (Configurable; In v49, when the jetpack exceeded a certain thrust power, it would cause the player to collide with themselves or invisible triggers, and explode as if they crashed even in open air)
• You no longer get stuck when trying to slide along the ground