Hints and Draw Settings panels were not removed during map closing/switching, which resulted in duplicate panels.
The way things were rendered during dragging is now used by default in Things mode.

Visual mode, "Select" action with "With the same texture" modifier: sidedefs are no longer selected when matching part has zero height.

When Draw Rectangle or Draw Ellipse mode is enabled, it's settings are now shown in side panel.
Draw Ellipse mode: increased maximum number of sides to 512.
Changed the way tags are shown in Tag Selector controls. Tags without labels are now shown as a number (not "Tag N"), and tags with label are now shown as "N (label)", not "label (N)".
Tag labels are now shown in Thing, Sector and Linedef info panels.
Once again changed the way things are rendered while dragged.
Rearranged the label in PairedIntControl and PairedFieldControl (it is now behind numeric controls).
Optimized MapSet.GetSectorByCoordinates().

Sectors mode, rectangular selection: you can now hold Alt to select things inside of selected sectors.
Sector highlight is now shown when selecting sectors in Tag Explorer.

Visual mode: using "Select" action with "select with the same texture" modifier in some cases selected middle texture when it shouldn't have.

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".

Nodes Viewer: ZNODES were properly shown only on freshly opened maps.

Sector highlight is now shown in many more places.
Edit area auto-focusing is now disabled when any form is open.

Fixed a crash when enabling Nodes Viewer mode in an unsaved map.

Fixed: texture size label's visibility was inconsistent in ImageSelectorControls.

Program version, including revision number, is now updated and handled properly.

We should copy middle texture to upper/lower parts regardless of whether they are actually required when AutoClearSidedefTextures is disabled, I suppose (aaaaand there was a logic error there).

Reverted "Delete Item" action to the way it worked in DB2.
Added "Dissolve Item" action, which works the way "Delete Item" worked in previous revisions of GZDB.
Added "Auto Clear Sidedef Textures" action, "Edit" menu and toolbar button, which toggle automatic removal of sidedef textures when floor or ceiling height is changed or when geometry is drawn, copied or pasted.
Draw Settings panel: upper/lower texture overrides can now be used.
Draw Settings panel: added 2 sets of buttons, which allow to quickly set or clear textures in current selection.
Things are now rendered behind AND on top of the grid/linedefs/vertices when they are dragged.
Redesigned hints system. They are now shown in a side panel.
Edit area auto-focusing is now disabled when script editor is open.
Texture Browser form: no texture group was selected when opening the form in some cases.
Fixed several strange/misleading text messages.

Action descriptions: added "disregardalt" parameter.

Visual mode: added "Match Brightness" action.
DECORATE parser: actor names, which contain "+" and "-" symbols, are now parsed correctly.
Fixed an error in lump ranges creation logic.
Cosmetic fixes in various warning/error messages.
Updated documentation.

Added hints for Drag Geometry modes.

Classic modes: bilinear filtering was used in full brightness mode regardless of preferences setting.
Classic modes: "Paint Selection" and "Toggle Full Brightness" actions can now be used from any plugin.
Fixed possible crash in DECORATE actor color override logic.

Added info about DECORATE keys to documentation (Configurations -> DECORATE keys).

Fixed a bug in Line2D.GetIntersection(), introduced in r1854 (SHOULD... OPTIMIZE... MORE... CAREFULLY!!!11).
A couple of minor optimizations in Renderer3D.

Fixed a misleading hint.

Open Map Options and Map Options forms: resources can be added by dragging them on top of resources list.

UDMF map parser should work ~35% faster now.
Texture browser form: keyboard focus was not updated when switching between textures using Tab key.
"Graphics" folder is now checked when searching for texture patches.
Various cosmetic changes here and there.

Info panel was not updated after leaving Visual mode.
Moved hints logic to ClassicMode, so hints can be displayed by any plugin.
Visual mode: dynamic light animation was not working.
Minor performance improvements in Actor, Configuration, UDMF and TEXTURES parsers.

Increased performance when creating new map geometry (for example, when applying changes made by "Draw Line", "Draw Rectangle" etc. actions).

Sector and Thing Info panels: fixed possible crash when trying to show unknown thing/sector flag.
Hints were not shown properly when multiselection was started while highlighting a map element.
Copy/Paste actions work much faster now.
Classic modes: rendered grid size in now adjusted to current zoom level.

Increased performance when deleting things in Things mode, linedefs in Linedefs mode and sectors in Sectors mode.
Increased performance when canceling Edit mode after pasting.
"Export to Wavefront .obj" function: current selection is now converted to sectors before running the function (previously it would export selected sectors when there were sectors selected, or the whole map when no sectors were selected).

Things mode: selection info was not updated when selection was cleared.

Updated hint system.
Corrected 2 typos in action names.

Info panel: current mode name was shown when in shouldn't have been.