Fixed a regression crash on Linux when almost finished loading a map

Prevent crashes with steamworks library when used too early on dedicated servers

Fixed console spam about invalid sprite orientation when the sprite material is simply missing

Fixed HLTV clients being kicked due to mismatching SteamID

Fixed a crash to do with env_projected_texture's texture

Fixed some security issues reported on HackerOne

Remove unnecessary return value in WorldPickerMouseDisable hook so GM:VGUIMousePressAllowed hook works more reliably for addons (Community Contribution)

Fixed Lua error with creator tool when trying to spawn NPCs that do not exist on the server (Community Contribution)

Blocked .vdf and specific .cfg files from being accessible by the Lua file library

Added one more known Lua backdoor URL to HTTP blacklist

Increased default value of mem_max_heapsize to 512, and block it from being changed by Lua API

Block datacachesize convar from being changed by Lua API, to prevent crashes when set to invalid values

Fixed monitor (and potentially other) materials in Hammer acting strangely when using "Fit" option in texture application tool.