UDMF light editing in GZDoom Visual mode: sector brightness is changed instead...

UDMF light editing in GZDoom Visual mode: sector brightness is changed instead of "lightceiling" property if targeted ceiling is part of 3D-floor.
UDMF Controls: increased precision of position and scale controls numeric inputs to 2 decimal places.
Sector/Linedef info panels: in some cases incorrect default values were shown for scale.
Sector/Linedef info panels: numbers are formatted more properly.