MAPINFO: added "DoomEdNum" and "SpawnNums" blocks support.
MAPINFO: added "#include" directive support.
MAPINFO: added "$gzdb_skip" special comment support.
DECORATE: "spawnthing" Game Configuration block is now updated using "SpawnID" actor property.
Game configurations: added "class" property to the most of ZDoom things.
Actions: removed "Reload MAPINFO" action.
Documentation: merged "GLDEFS and MODELDEF support", "(Z)MAPINFO support" and "TEXTURES support" topics into "(G)ZDoom text lumps support", added info about the other text lumps GZDB can use.
