Fixed, Texture Browser Form: well, I broke "Tab" key functionality again (in previous commit)...
Maintenance: changed curly braces style to match DB2 one (hopefully not breaking anything in the process...).
Maintenance: changed private method names casing to match DB2 one.
Fixed: Randomize Sectors, UDMF: vertex height changes were not undone properly after using the mode (I broke it in r2101).
Fixed: Randomize Sectors: floor/ceiling textures can not be used as lower/upper textures when "MixTexturesAndFlats" is disabled. In this case the corresponding option is now changed to "Use default texture".
Visual mode: "Copy Texture", "Copy Texture Offsets" and "Copy Properties" actions now always copy properties from currently highlighted surface (previously they copied properties from the first selected surface when something was selected).
Draw Rectangle mode: nothing was drawn in some cases.
Drag Things mode: grid was not updated when grid size was changed in this mode.