Add support for other engine binaries in game configs (#1414). (#1626)

* Add support for other engine binaries in game configs (#1414).

* Add engine bin path for CRC bin lookup and filter out addons from GAMEBIN.

* MAX_PATH -> PLATFORM_MAX_PATH.

* Fix library lookup on Linux.

Before this, there was a bad assumption that, like on Windows, POSIX module
handle pointers were within the module's address space (and thus usable
with dladdr). That's not true!

Instead, to get a usable address on all platforms, we'll do a lookup of the
CreateInterface function that exists in all modules. This also has the
(arguable) benefit of further locking this implementation to modules owned
by the game.

To get a valid address inside the module now on both p

bridge/include/CoreProvider.h

@@ -86,11 +86,6 @@ public:
 	const char		*gamesuffix;
 	/* Data */
 	ServerGlobals   *serverGlobals;
-	void *          serverFactory;
-	void *          engineFactory;
-	void *          matchmakingDSFactory;
-	void *          soundemittersystemFactory;
-	void *          vscriptFactory;
 	SMGlobalClass *	listeners;
 
 	// ConVar functions.

bridge/include/IFileSystemBridge.h

@@ -56,6 +56,7 @@ public:
 	virtual void RenameFile(char const *pOldPath, char const *pNewPath, const char *pathID = 0) = 0;
 	virtual bool IsDirectory(const char *pFileName, const char *pathID = 0) = 0;
 	virtual void CreateDirHierarchy(const char *path, const char *pathID = 0) = 0;
+	virtual int GetSearchPath(const char* pathID, bool bGetPackFiles, char* pPath, int nMaxLen) = 0;
 };
 
 } // namespace SourceMod