UDBScript: groups all classes, objects, and methods in a new UDB namespace, usable with the new feature version 4. Updated the documentation accordingly. Resolves #679

Added classic rendering mode to closer emulate software renderer visuals in visual mode

Added "Orbit" and "Move Camera to Cursor" visual mode actions (not bound by default)

Script run by UDBScript are now executed asynchronously

UDBScript: fixed a bug where Map.nearestLinedef, Map.nearestThing, Map.nearestVertex, and Map.nearestSidedef would not return valid objects when no nearest map element was found

Fixed a crash with Mono that happened because of the placeholder text in the "additional parameters" text box in the testing drop down menu. Fixes #677

Event lines are now shown between things and map elements even if the thing doesn't have an action, but directly uses its args. Resolves #676

UDBScript: Exported the classes Linedef, Sector, Sidedef, Thing, and Vertex, so that they can be used with instanceof
UDBScript: Map class: the getSidedefsFromSelectedLinedefs() method now correctly only returns the Sidedefs of selected Linedefs in visual mode (and not also the highlighted one)
UDBScript: Map class: added a new getSidedefsFromSelectedOrHighlightedLinedefs() method as the equivalent to the other getSelectedOrHighlighted*() methods
UDBScript: Sector class: added new floorSelected, ceilingSelected, floorHighlighted, and ceilingHighlighted properties. Those are mostly useful in visual mode, since they always return true when the Sector is selected or highlighted in the classic modes. The properties are read-only
UDBScript: Sidedef class: added new upperSelected, middleSelected, lowerSelected, upperHighlighted, middleHighlighted, and lowerHighlighted properties. Those are mostly useful in visual mode, since they always return true when the parent Linedef is selected or highlighted in the classic modes. The properties are read-only
UDBScript: added new example to apply textures for floor/ceiling and upper/middle/lower texture for selected map elements
UDBScript: updated documentation

Eternity Engine game configuration: removed the lightfloorabsolute and lightceilingabsolute fields from the sector flags, so that they are handled correctly. Fixes #670

Improved associations between arbitrary UDMF fields (used by the Eternity Engine game configuration)

Find and Replace Mode: fixed a problem where linedef activation flags could not be found or replaced. Fixes #667

* Updated the bundled Zandronum ACC with Zan 3.1 changes

* Add Zandronum 3.1 functions and constants to its ACS configuration

* Updated the Zandronum ACC (again), as it was missing GAMESTATE definitions

When choosing a difficulty or engine in the test toolbar button the engine will not be launched immediately. This can be reverted in the preferences. Resolves #626

UDBScript: fixed a problem where a version warning was shown then the script version was not equal to the UDBScript version (instead of only showing the warning when the script version was higher)

UDBScript: the methods of the Pen class now return the instance of the Pen class to allow method chaining. Resolves #662

IPK3 and IPK7 with an IWADINFO lump with a single IWAD definition are now recognized as the main resource file (used for the -iwad parameter when testing). Fixes #653

Hexen Game Configuration: fixed a problem where the default arguments of the Death Wyvern had special names, even though they actually don't do anything in game. Also renamed the thing from "Dragon Lich" to the correct "Death Wyvern". Fixes #660

UDBScript: fixed a problem where using QueryOption resulted in an exception being thrown. Fixes #661

ZScript: user variables of parent actors were not displayed in the custom tab of the thing editing dialog. Fixes #649

Fixed a problem where DeHackEd lumps failed to parse when their header wasn't at the beginning of the file. Fixes #647

Drag Geometry Mode: floor and ceiling panning are now correctly preserved when dragging geometry. Fixes 648

Added map scripting capabilities to UDB (#656). Documentation at https://biwa.github.io/udbscript-docs/

ZScript parser: fixed a bug where trying to parse the undocumented alternative array declaration syntax failed. Fixes #645

Fixed an issue where thing positions were modified even when the new position was the same as the old one. Fixes #644