Visual mode: "Lower/Raise Floor/Ceiling" actions now work on surfaces with sector slopes.
Cosmetic: numeric textboxes, which support relative values, now have differently colored text and a tooltip.
Internal: renamed Sector.CeilingSlopeOffset to Sector.CeilSlopeOffset, Sector.CeilingSlope to Sector.CeilSlope to match their names with similar sector properties.
Sector Edit Form (UDMF): sector brightness value was processed incorrectly when relative value was entered.
Internal: added "ButtonStepsWrapAround" property to ButtonsNumericTextbox.
Internal, SectorEditFormUDMF: more changes to Slopes tab. Still not operational...
Numeric textbox: in addition to '++NN' and '--NN', you can use '*NN' and '/NN' to multiply or divide the values.
Configurations, ZDoom_linedefs.cfg: some linedef action arguments were missing a proper type.
Rewritten parts of hints system. Hints are now loaded from "Hints.cfg" file.
