Sectors Mode: fixed a problem where dragging a single highlighted sector did not move the things in the sector when synchronized things editing was enabled

Added autosaving of the current map. Autosaving happens in intervals when the map is changed. It will not overwrite the current map, but rather create new files, just like backups. Autosaving interval and number of files can be configured in the "Recovery" tab of the preferences. Autosaving can also be disabled there (not recommended). Autosaves will not have their nodes built for performance reason.

3D Floor Mode: fixed a problem where the previous state of linedef arguments were not preserved for undo snapshots. Fixes #967

Sound Propagation Mode: fixed a problem where removed sector geometry was still shown when undoing/redoing. Fixes #992

Visual Mode: fixed a problem where texture skewing didn't work correctly for textures scaled through sidedef properties. Fixes #985

Visual Mode: added support for GZDoom style texture skewing

Sound Propagation Mode: fixed a crash when things were outside the map's geometry bounding box. Fixes #975

Visual Mode: the effect of slope things are now only applied if they are specified in the game configuration

Game Configurations: added support for enabling or disabling support for vertex heights in UDMF game configurations

Visual Mode: fixed a problem where flood selection did not work correctly when sidedefs were previously marked by other actions

Visual Mode: fixed a problem where flood selection would operate from all selected surfaces and not just the clicked on one. This behavior can be reverted by enabling the "Use buggy flood select in Visual Mode" option in Preferences -> Editing (#969)

Visual Mode: fixed a problem where flood selection would operate from all selected surfaces and not just the clicked on one. This behavior can be reverted by enabling the "Use buggy flood select in Visual Mode" option in Preferences -> Editing

OBJ Exporter: fixed a problem where the wrong textures were used on 3D floors when they have the "use upper/lower texture" flag set

Visual Mode: fixed a problem where floors/ceilings could not be changed in size if the user tried to change their texture offset in a non-UDMF map

Visual Mode: changing brightness now affects sector brightness, holding Alt will change local brightness

Visual Mode: fixed a problem where sloped 3D floors with an alpha value of less than 128 were not shown at all instead of fully opaque. Fixes #954

Draw Curve Mode, Draw Ellipse Mode, Draw Rectangle Mode: added option to place things at the designated vertex positions instead of drawing geometry (#956)

Point Thing at Cursor: check for a thing's fixedrotation rather than its category's arrow setting (#957)

Visual Mode: when applying camera rotation and pitch to things a status message will now be displayed. Fixes #955