3.1.13

General

• Updated ZDoom, MAPINFO and ACS language definitions (thanks @Blue-Shadow)
• Updated SRB2 Lua language definition (thanks @SteelTitanium)
• Added extra UDMF flags (thanks @Gaerzi)

Texture Editor

• Fixed an issue with the 'optional' keyword in TEXTURES

Map Editor

• Various improvements and fixes to texture handling and precedence (thanks @Talon1024)