Mapbase v5.1

- Fixed a major oversight in Source 2013 which was causing some code to think all logic entities were worldspawn
- Added WIP background nodraw for point_cameras set to not draw skybox at all
- Fixed map-specific talker not flushing on restore
- Added optional HUD hint to code-based game instructor hints
- Added workaround for suspicious crashes in HL2 NPC rappelling code (reported by 1upD)
- Made antlions summoned by npc_antlionguard report as dead when removed with the "Kill" input
- Fixed math_mod not saving mod value (reported by Klems)
- Added SDK_WindowImposter, which uses the SteamPipe cubemap bug workaround and includes support for parallax corrected cubemaps
- Updated thirdpartylegalnotices.txt to mention the Squirrel API
- Fixed incorrect type checking for script instances in VScript
- Added a bunch of new misc. VScript constants
- Added a few new base VScript functions
- Added a separate "Clientside Script Language" keyvalue to worldspawn for VScript, allowing client scripts to use a different language from server scripts
- Fixed worldspawn crashing the game when running entity scripts (reported by krassell)
- Fixed manifests creating a second worldspawn, allowing them to function properly in HL2
- Added tons of remapping-related fixes for instances and manifests, including node IDs and overlay remapping
- Added a keyvalue to func_instance which allows vector axis lines to be remapped properly
- Added support for manifest root path instances in VBSP
- Added missing PrintBrushContents() contents to VBSP
- Added -nohiddenmaps parameter
- Made manifest cordon somewhat functional

CONTRIBUTING

@@ -25,8 +25,10 @@ All contributions must follow the following rules:
  * All content in a contribution must be either already legally open-source or done with the
    full permission of the contribution's original creator(s).
    
+ * Contributions must not break existing maps/content or interfere with them in a negative or non-objective way.
+   
  * Code contributions are not obliged to follow Mapbase's preprocessor conventions (e.g. #ifdef MAPBASE),
-   although it is acceptable.
+   although following them is acceptable.
    
  * If you are contributing a file you created yourself specifically for Mapbase, you are required to
    use the custom "Mapbase - Source 2013" header used in other Mapbase files as of Mapbase v5.0.