Decoupled plane equation slopes from sector heights. This means that changing sector heights will not change those slopes (use the offset box in the "slope" tab of the Edit Sector Dialog instead)

Fixed a crash that would happen when the line slope things (9500/9501) are used but the linedef they are tagged to doesn't have a front sidedef. Fixes #398.

Added option to select behavior (Tools -> Preferences -> Editing) of scaling when auto-aligning textures on floors/ceilings (use base scale of 1 (default), use current scale as base, never scale)

Aligning textures on the X axis now works correctly with negative scale values when world panning is not enabled.

Fixes for raisesectortonearest and lowersectortonearest action when used on slope handles to account for float rounding errors

The sloping between handles action is now a bit more convenient and tries to figure out what the user wants to do even if not exactly two slope handles are selected.

- Smart pivot handles are now shown for the highlighted slope handle

- Added action to slope selected floors/ceilings between selected slope handles (default key: Ctrl-F)
- Added Shift-W as default key to toggle visual slope picking

- If geometry is selected and the geometry the modified slope handle belongs to is not selected it will now also be modified
- Made the slope handles hover closer to the geometry

Improved drawing length of slope handles on sloped lines (still too short, possibly because of aspect ratio correction?)

The slope handle closes to the mouse cursor will now always be picked (no minimum distance required anymore)

Also fixed some cases where slopes were applied incorrectly

Load previews when they are accessed

Fixed a problem where negative Y scales of sidedefs would result in a wrong offset when auto-aligning

- Fixed a problem where the wrong plane was assigned to ceiling surfaces

Fixed a bug where flats on a 3D floor could not be auto-aligned (auto-aligning the flats of the tagged sector instead). Fixes #338.

Fixed an issue where selected objects were unnecessarily cleared in visual mode, resulting in slowdowns. Partly addresses #337.