A small hotfix for P2CE:
- Fixed crash loading certain valid textures
- Removed unnecessary campaign-related assets from release
- Added empty ChapterBackgrounds.txt to override Portal 2's
- Added compile tools benchmark scripts
- Don't load mounts.kv if -nousermount or -safemode is passed to the game
- Added brae's get_hammer_content and get_latest_js_types scripts, and ported them to PowerShell
- The convert_bik_to_webm PowerShell script should now work on UNIX platforms
- Update install_hammer script's downloaded dependencies