Petite mise à jour L4D

From Jason Ruymen

A required update for Left 4 Dead is now available. Please run hldsupdatetool to receive. The specific changes include:

- Fixed a crash related to a Crash Course achievement
- Fixed an issue were bots and computer controlled special infected were being reported via « View Game Info »
- Added Team Versus 4 on 4 competitive matchmaking

Linux:
- Add warning if +map is not specified on the command line
- Steam is located by searching .., . and $PATH
- Added -steambin option to specify location steam, overrides search
- Added -steamverify option to add -verify_all when updating with steam

Jason