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

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

Visual Mode: fixed an issue where trying to apply a rotation to things that were not seen yet would cause a crash

Visual Mode: fixed a problem where the selection order was not kept when synchronized selection between visual and classic modes was enabled. Fixes #938

Visual Mode: fixed a problem where things directly touching the top of 3D floors were rendered with the incorrect brightness. Fixes #940

Visual Mode: changes to Eternity Engine's upper/lower texture skewing definitions are now shown in Visual Mode

Visual Mode: fixed a crash when toggling visual vertex slope picking and the map contains double-sided linedefs without a front sidedef. Fixes #928

- fixed a rare condition where skewed mid textures were not clipped correctly
- fixed a problem where translucent mid textures were not skewed correctly
- fixed a problem where sprites were skewed unintentionally

Disabled visual sloping for game configurations that do not support plane equation slopes. Fixes #828
Added toasts for visual sloping events

Behavior can be configured in the "Toasts" tab in the preferences.

Visual Mode: fixed an issue where using the "apply camera rotation to things" action did not update the thing cages properly

Visual Mode: Fixed a problem where using visual sloping a slope handle around itself resulted in invalid slopes