Error checks: added "Check unused textures" option.
Replaced MissingTexture3D and UnknownTexture3D.
Sectors mode: restored "Lower/Raise Floor/Ceiling by 8 mp" actions.
Visual mode: in some cases sidedefs were rendered as selected when they were not.
Existing linedefs were not split while drawing new lines in some cases.
Texture and height overrides were not applied correctly in some cases.
Preferences form: "Ctrl+Alt+ScrollUp" and "Ctrl+Alt+ScrollDown" dropdown items were setting the shortcut to "Ctrl+Shift+ScrollUp" and "Ctrl+Shift+ScrollDown".
Visual mode: added support for "fogdensity" and "outsidefogdensity" MAPINFO properties.
Sector Info panel now shows the number of sector's sidedefs as well as light and fade colors (UDMF only).
UDMF: Sector and sidedef flags are now copied/pasted when using "Copy Properties" and "Paste Properties" actions.
Fixed: in some cases default texture overrides were used even when corresponding option was disabled.
Sector Edit form: light and fade values were not saved when a value was pasted/entered into text box.
Sector Edit form: "reset value" button was not shown for light and fade values when selected sectors had different light/fade colors.
Reverted Open Map form changes from previous commit (my assumption that map marker is always empty was not correct...)
Updated documentation.
Textures were not loaded properly from PK3/PK7 archives.
Visual mode: restored ability to remove textures using Delete action.
Visual mode: fixed several bugs in Cut/Copy/Paste things actions.
Visual mode: vavoom style 3d floors were not displayed properly.
Visual mode, 3d floors: added support for "RestrictLighting" (2) flag.
Visual mode, 3d floors: inner sides of 3d floors with "swimmable"/"render inside" flags used incorrect brightness value.
