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

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 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.

- Auto-aligning textures now produces more intuitive results and is consistent between UDMF and non-UDMF maps

- Slope effects related to slope things are now displayed more correctly in visual mode (they were not applied at all). Fixes #160
- Slope effects of UDMF vertex heights are now displayed more correctly in visual mode (they could be overwritten by lower tier slopes)

- Added option to enable additive paint selecting without holding shift independently from regular additive selecting

- Textures will now wrap correctly in visual mode when the flag of the Line_SetIdentification special is set in Hexen format. Fixes #271

- Improved support for auto aligning scaled textures

3D floors are now updated in real time in visual mode when their control sector is sloped through the line slope action. Fixes #250.

- Dialog can't be resized anymore
- Dialog can be canceled by pressing the escape key
- Changed input boxes to the appropriate GZDB version, so steps and modifier key work correctly
- Added checkboxes to automatically fit the textures optimally based on the width/height of the line(s) in respect to the width/height of the texture
- Added input boxes to manually set a width/height pattern size of the texture that will be used when automatically fitting textures

Fixed: cutting a thing in visual mode would leave disposed BaseVisualThings in the selection. (reported by DOOMGABR)

Fixed: changing brightness of upper/lower/middle sidedef did not update the whole sidedef brightness until 3D mode restart