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.

[patterns]
**.h = native
**.c = native
**.cpp = native
**.lua = native
**.txt = native
**.pas = native
**.inc = native
**.hs = native