Import Wavefront .obj as Terrain mode: floor height of each created sector is now set to the average height of an .obj polygon it was created from.
Import Wavefront .obj as Terrain Settings window: added "Use slopes" checkbox. When enabled, the mode will create slopes using vertex height offsets (UDMF) or Floor Vertex Height things (1504).
Fixed, Visual Mode: things were rendered at wrong height after using "Lower/Raise Height" actions in sectors with sloped floor (or ceiling for ceiling-aligned things)
Fixed: info panel was not updated after switching to another Edit Mode.
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.
Added icons for "Save Screenshot" menu items.
Development: "Save Screenshot (active window)" action will work on a child Form only if it is inherited from DelayedForm.
Draw Settings panel: added "All" buttons to "Fill Selection with Textures" and "Remove Textures form Selection" groups
Export to .obj: fixed a crash when trying to export an unsaved map.
Texture preview are now created ~25% faster.
