Eternity Engine configuration: moved portal related sector flags to the portals tab of the sector edit form

Error Checker: added config options to ignore unknown textures on sidedefs for certain actions. Resolves #518

CEMPOIS (base)
PLANET1 (base)
SP_DUDE3 (marble)
SP_DUDE6 (marble)

These textures only appears in IWAD
doom.wad and not doom2.wad.

Remove unused Zandronum_texturesets.cfg

The texture browser categories for Doom
are focused on Doom 2. This also categorizes
some entries that only appear in Doom 1.

Unfortunately it looks like the new filters
will only be applied on fresh UDB installs.
Existing installs must click the
"Add Default Sets" button under the "Textures"
tab for their Doom 1 game configs.

Added preliminary DECALDEFS support. Parsing works, indexed decals and decal groups can be selected as the first argument of the Decal thing. Decals are not displayed in Visual Mode, decals without an index are not supported

Hexen game configuration: corrected an error where things 78 ("Tall Tree 1") and 79 ("Tall Tree 2") had their sprites interchanged

Heretic game configuration: actions 28 and 33 now correctly state that they are for green keys instead of non-existing red keys. Fixes #468.

Added action 109:Light_ForceLightning to Hexen configuration. Also changed the description of the parameters in the ZDoom configuration to make it more clear what it does. Fixes #459.

Added the "nocount" UDMF thing flag (as "No completion count") that was added in GZDoom 4.4.0 to the ZDoom config. Fixes #422.

Hexen/UDMF linedef action 28 is now correctly labeled "Floor Raise And Crush" instead of misleading "Floor Crusher Start". Fixes #386.

This reverts commit 2e146309.

- (G)ZDoom action 51:Sector_SetLink is now flagged to not require an activation, since it's mostly used statically

* Flags and Railgun taken from zdaemon.wad.

Thanks to ZDaemon team for the sprites.

* ZDaemon Flags and Railgun.

- Improved the wording for the "hidden" UDMF sector flag to make clear that it only hides the sector on the textured automap

Moved spotlights to separate directory;  fixed parameter names;  added animated spotlights to game configurations

Did some maxcode refactoring about dynamic lights;  added initial spotlight support (at least they are recognized as lights now)

* Replace the wrong portal_ceil_alpha and portal_floor_alpha with alphaceiling and alphafloor.

* Added the new fields of Eternity 3.42.03

Fixed: flipped +USEACTORPITCH direction for recent GZDoom versions;  this can be reverted by putting "buggymodeldefpitch = true;" in the game configuration for your specific projects if they are using old GZDoom versions.  Note: already added for Zandronum.

Replace the wrong portal_ceil_alpha and portal_floor_alpha with alphaceiling and alphafloor. (#101 by printz)

Made Skulltag item sprites optional to support default Skulltag+Zandronum config without producing 100 errors

Updated Zandronum game configurations to include invasion spawners and MBF items (dog, evil sceptre, unholy bible, beta lost soul)

Added: proper GUI tab for color-related sector properties. The tab now hosts Doom64 lighting as well as old color-related things (floor/ceiling glow, light color, fade color and desaturation).

Fixed: inheritance from game configuration for dynamic lights; Fixed: visual representation of inherited lights (reported by Nash); Fixed: inherited thing arguments from game configuration; Added: //$ClearArgs for clearing inherited arguments.

Fixed: forgot to add ZDaemon_common.cfg; Fixed: Internal: removed hardcoded arg0str only for scripts