Edit Linedef dialog (UDMF): fixed a problem where the back sidedef's controls were not disabled correctly if their UDMF fields were not set in the game configuration

Added ability to enable/disable controls in the UDMF map element editing dialogs based on UDMF fields specified in the game configurations (#953)

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

UDMF type handler: fixed a problem where default values provided as integers for floating point fields failed to convert properly

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

Fix SOC errors being displayed as Lua errors

Text file parser: fixed a problem where parsing could fail if the file ended with a comment without an trailing newline

Game Configurations: fixed a crash when no default values for UDMF integer or  floating point fields are set

Game Configurations: UDMF integer and floating point fields can now have default values other than 0

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

Game configurations: renamed lightmap things from static to lightmap. Added pulsing, flickering, and random flickering lightmap things

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

Game Configurations: fixed a problem where the enum list of enum bits handlers was not set for UDMF fields

- Added unique sprite sprites for custom rows/circles of items
- Set default values for hoops and custom rows/circles of items

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)