Fix low gravity utility not working in Gravity script (fixes #13)
Using low gravity halves the gravity.
For using a range, both the minimum and maximum gravities are halved.
Negative gravities are doubled.
Bonus: game modifier “low gravity” will be force-disabled.
Hermes
Fry
Zoidberg
Wong
Nibbler
Conrad
Amy
Billy
West
Katey
Sagal
Dimaggio