Update README.md build.yml [skip ci]

CalcSurfaceExtents: Fixed a fatal error on some maps due loss of floa…

…ting point

CMakeLists.txt: Configure for compat oldest libstdc++

CMakeLists.txt: Add -fno-stack-protector
ExecuteString: Fix parser
build.yml: Add paths-ignore README.md

Fix local-buffer overrun, may undefined behavior with hitbox blending…

… or crash (reverse-engineering mistake)

Fix crash MSG_ReadFloat

Graceful shutdown on sigterm (rehlds#776)

* Add players kick on SIGINT \ SIGTERM
* Add SIGINT & SIGTERM handling linux console
* change shutdown method

SV_ProcessFile: Wrap Con_Printf in Con_NetPrintf to avoid spam in HLD…

…S console

Implement `svc_exec` support in the engine and HLTV (rehlds#737)

* Added `svc_exec` to the list of svc commands in engine
* Added `svc_exec` support to HLTV code
* Made the engine code forward-compatible with future svc_* additions
* Added reserved svc_* slots in the enumerations

Don't add an invalid decal into custom.hpk, otherwise clients may cra…

…sh because they have no safe-checks WAD3 MIP-Header.

Related rehlds#755 (Only fixes server-side)
Fixes rehlds#757

Add extra checks to validate WAD3 MIP-Header. (rehlds#755)

* Add extra checks to validate WAD3 MIP-Header.