Don't use thread unsafe collections in threaded code (hopefully fixes crash in Sectors Mode when selecting sectors)

3D Floor Mode: only 3D floors with the "user_managed_3d_floor" field set to true will be modified in UDMF maps

Resetting a slope in Sector Edit Form UDMF or with the Reset Slope action will not set the height to the z position at the center of the sector anymore, but to its original height

Increased performance on multi-core CPUs when selecting sectors in Sectors Mode when Synchronize Thing Editing is enabled

Added some sanity checks for maximum number of entries in the VERTEXES/SIDEDEFS/LINEDEFS/THINGS lumps for the binary map formats

Fixed a problem where saving a map would hang when the nodesbuilder produced too much output on stdout and strerr. Fixes #417. Fixes #498

Added fixes for the stuck thing checker for the Eternity Engine configuration (thanks for hawkwind3). Fixes #551

Map Analysis Mode: fixed a problem where checking for stuck things works incorrectly in some situations (thanks to hawkwind3). Fixes #469

Sector Edit Form UDMF: fixed a bug where resetting a slope when the sectors doesn't have a slope resulted in a nonsensical sector height

https://doomwiki.org/wiki/Static_limits

The VPO limit is raised by Hexen (160) & Strife (200)
so make it configurable in the basegame.

The hover tooltip will reflect the adjusted max
limit and the heatmap is interpolated to 0-255
for the 256x10 visplane_pal.png colour range
gradient.

Boom's linedef special 260 allows a 64K
translucency lump to be applied to the
front sidedef's midtex for applying a
custom 1 to 99% translucency value. Stop
reporting this as an unknown texture.

https://doomwiki.org/wiki/Vertical_offsets_are_ignored_in_texture_patches

BIGDOOR7 & STEP2 in doom.wad and doom2.wad contain
negative Y-offsets some a patch but instead the
renderer defaults to Y-offset value of 0.

This stops UDB's 3D visual mode from using the
negative value - change it to 0 to match the game
renderer. (G)ZDoom behaves the same as vanilla.

Stop calling ScriptFileDocumentTab.RemoveTrailingWhitespace()
on a text editor that has unchanged text. This causes the
currently-opened map to be marked 'isChanged == true' when
nothing is modified.

Program preferences are now saved as soon as the configuration dialog is closed
Recent files are now saved as soon as an existing map is loaded

Sector/Linedef/Thing/Vertex Edit Form: the map will not be marked as changed anymore when canceling changes made in the forms, when the map wasn't marked as changed before
Copying map elements doesn't mark the map as changed anymore if the map wasn't marked as changed before copying

Curve Linedefs Mode: fixed a problem where the curve would not flip when being dragged with the mouse

OBJ Exporter: unchecking the "Generate ZScript/DECORATE" and/or "Generate MODELDEF" checkboxes will now really not generate the respective files

Updated ZDaemon ACS configuration (thanks to DoomKrawa)

Several new ZDaemon ACS function added (thanks to DoomKrawa).

OBJ Exporter: fixed a problem where concave sectors with exactly four corners were not exported correctly. Fixes #249

Script Editor: fixed a problem where folded blocks were unfolded unexpectedly when the script was saved. Fixes #392

Linedef Editing Form (UDMF): fixed a problem where activation checkboxes were shown red for actions that don't require activation

Map Analysis Mode: checking for missing activation flags (UDMF) now finds linedef that are missing an actual activation flag, not only lines without any flags in that group. Fixes #288
Linedef Editing Form (UDMF): now only missing required activation flags are marked red

Added support for only enabling editing modes when the current game configuration supports the features. Currently only applies to 3D Floor Mode, Slope Mode, and Draw Slope Mode. Fixes #463

Slope Mode, Draw Slopes Mode: both modes are now deprecated as they are superseded by visual sloping. The modes will be removed in the future. Entering the modes will add a warning to the Errors And Warnings dialog

3D Floor Mode: added option to use Synchronized Things Editing when (de)selecting sectors. Resolves #443

Visual Mode: fixed inaccuracies of when upper/lower textures are shown when sky rendering is enabled

Fixed a bug where pasting texture offsets in UDMF configurations without support for local sidedef texture offset (like the Eternity UDMF configuration) didn't work. Fixes #538

Fixed a bug where trying to align the grid to a linedef or setting the grid origin to a vertex would crash when no map was opened. Fixes #536

Such an event invokes every unbound action.